Basic Emotions

[Petter]

https://neuro.psychiatryonline.org/d...np.23.2.jnp121

The anterior cingulate cortex (ACC) lies in a unique position in the brain, with connections to both the “emotional” limbic system and the “cognitive” prefrontal cortex. Thus, the ACC likely has an important role in integration of neuronal circuitry for affect regulation and can be identified as a distinctive region in understanding psychopathology. Affect-regulation, the ability to control and manage uncomfortable emotions, is a primary goal for mental health clinicians in treating psychopathology. Avoidance of painful emotions is often the motivating force in negative behaviors such as substance abuse, binge eating, and suicide. These actions are taken as part of maladaptive approaches to control, avoid, or regulate painful emotions. Clinicians often treat patients by helping them to develop more adaptive coping mechanisms in regulating their emotions. Understanding the processes by which ACC contributes to regulation of emotions may assist clinicians in their therapeutic work.

pgACC pregenual anterior cingulate cortex.png

OFC.jpg

[Petter]

https://www.researchgate.net/figure/...fig1_292995087

The anatomy of the human reward system (From National Institutes of Drug Abuse (NIDA)) PFC – prefrontal cortex; ACG – anterior cingulate gyrus; OFC – orbitofrontal cortex; SCC – subcallosal cortex; NAc – nucleus accumbens; VP – ventral pallidum; Hipp – hippocampus; Amyg – amygdala

the anatomy of the human reward system.png

[Petter]

https://www.nature.com/articles/s41467-022-35211-7

A circuit from the ventral subiculum to anterior hypothalamic nucleus GABAergic neurons essential for anxiety-like behavioral avoidance

Behavioral observations suggest a connection between anxiety and predator defense, but the underlying neural mechanisms remain unclear. Here we examine the role of the anterior hypothalamic nucleus (AHN), a node in the predator defense network, in anxiety-like behaviors. By in vivo recordings in male mice, we find that activity of AHN GABAergic (AHNVgat+) neurons shows individually stable increases when animals approach unfamiliar objects in an open field (OF) or when they explore the open-arm of an elevated plus-maze (EPM). Moreover, object-evoked AHN activity overlap with predator cue responses and correlate with the object and open-arm avoidance. Crucially, exploration-triggered optogenetic inhibition of AHNVgat+ neurons reduces object and open-arm avoidance. Furthermore, retrograde viral tracing identifies the ventral subiculum (vSub) of the hippocampal formation as a significant input to AHNVgat+ neurons in driving avoidance behaviors in anxiogenic situations. Thus, convergent activation of AHNVgat+ neurons serves as a shared mechanism between anxiety and predator defense to promote behavioral avoidance.

hypothalamus functions.jpg

hypothalamus functions 8.jpg

[Petter]

AHN and PVN: avoid a threat ... fear

LH: approach a reward ... excitement, interest

DMH and PH: approach an enemy or an obstacle ... anger

VMH: approach a partner

(see post #363)

[Petter]

PMN (the premammillary nucleus): social behavior ... enjoyment, euphoria (?)

[Petter]

https://www.ncbi.nlm.nih.gov/books/NBK525993/ (Neuroanatomy, Hypothalamus)

The mamillary nucleus contributes to the limbic system as part of the Papez circuit. It is also involved in memory formation and controls exploratory behavior.




https://en.wikipedia.org/wiki/Hypothalamus

posterior (mammillary), tuberomammillary nucleus ... lateral hypothalamus:

arousal (wakefulness and attention)

feeding and energy balance

learning

memory

sleep




https://en.wikipedia.org/wiki/Ventro...e_hypothalamus

The VMHdm has a role in the male vocalizations and scent marking behaviors.

The VMHvl contains many distinct neuronal populations that contribute to varying, often distinct, functions. Notably, this region plays a role in sexual behaviors in females (lordosis), thus stimulating their sexual arousal. The VMHvl has also been found to play a role in estrogen-mediated movement and energy expenditure/thermogenesis.




https://neuroscientificallychallenge...now-your-brain

Main nuclei of the hypothalamus. An, anterior nucleus; Ar, arcuate nucleus; DM, dorsomedial nucleus; L, lateral nucleus; MB, mammillary bodies; Po, posterior nucleus; Pr, preoptic nucleus; PV, paraventricular nucleus; SC, suprachiasmatic nucleus; SO, supraoptic nucleus; VM, ventromedial nucleus.




https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8463871/

Based on our hypothesis that preoptic inhibitory neurons as main regulators of parenting have a potential role in depression as well... (and Table 1)




https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8832877/

Our research reveals that PVN is a key brain area for controlling anxiety and arousal behaviors. We also provide a neurological explanation for anxiety disorder and insomnia...




https://www.nature.com/articles/nrn3952

The ventromedial hypothalamus (VMH) has been implicated in defensive behaviours, which animals adopt to avoid danger; however, its precise role and the underlying neural circuitry are unclear. Two new studies reveal the VMH to be a key orchestrator of multiple defensive behaviours in mice.




https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5770748/

Here, we provide an updated summary of the evidence that supports a role of the VMHvl in aggressive behaviors.




https://www.sciencedirect.com/scienc...96627314011349

* Activating VMHdm/c SF1 cells induces defensive-like motor and autonomic responses

* The VMH→PAG and VMH→AHN pathways mediate immobility and avoidance, respectively

* VMHdm/c neurons send collateral projections to the AHN and dlPAG

* AHN activation elicits escape jumping and avoidance, but not immobility

Many species develop coping strategies to avoid danger and to survive. Given that these defensive reactions are innate, the neural mechanism underlying these behaviors is likely hardwired. The hypothalamus plays a critical role in the expression of defense behavior (Bard, 1928). Decorticated cats display a mixed pattern of rage and defense responses, such as hissing and paw striking, only if the caudal hypothalamus is left intact. Conversely, classic electric and chemical stimulation experiments demonstrated that a pattern of somatomotor and autonomic responses that resemble the behavior of animals facing natural threats can be elicited from the medial hypothalamus in many species, including human (Fernandez De Molina and Hunsperger, 1962, Lammers et al., 1988, Lipp and Hunsperger, 1978, Schmitt et al., 1985, Silveira and Graeff, 1988, Wilent et al., 2010). In fact, there appears to be an interconnected hypothalamic defense circuitry, which comprises the anterior hypothalamic nucleus (AHN), the dorsomedial part of the ventromedial hypothalamus (VMHdm), and the dorsal part of the premammillary nucleus (PMd), that shows strong immediate-early gene responses in rats and mice exposed to live predators (Canteras et al., 1994, Canteras and Swanson, 1992, Dielenberg et al., 2001, Martinez et al., 2008, Risold et al., 1994).


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hypothalamus functions 5.jpg

hypothalamus functions 6.jpg

[Petter]

https://en.wikipedia.org/wiki/Preoptic_area

The medial preoptic area (mPOA) has been implicated in parental care in both males and females. In rats, oxytocin and vasopressin are associated with maintaining maternal care through local release in the mPOA and the adjacent bed nucleus of the stria terminalis (BNST). Oxytocin and vasopressin V1a receptor binding are increased in both the mPOA and the BNST in lactating rats when compared to controls.




https://www.researchgate.net/figure/The-neural-network-governing-social-behaviors-The-hypothalamic-pathways-that-regulate_fig4_283687294

The neural network governing social behaviors The hypothalamic pathways that regulate different innate behaviors are intertwined. Sensory cues emitted by pups, conspecifics, or predators are relayed via separate neural pathways within the posterior dorsal and posterior ventral divisions of the medial amygdala (MeApd and MeApv) to reach interconnected hypothalamic nuclei, the ventromedial hypothalamus (VMH), medial preoptic area of the hypothalamus (mPOA), premammillary nucleus (PMN), anterior hypothalamic nucleus (AH), and the forebrain structure, the bed nucleus of the stria terminalis (BST), resulting in different activation patterns of this neural network and consequently different motor outputs via the periaqueductal gray (PAG). Each colored shape corresponds to a nucleus of anatomically similar shape. The VMH is divided into the dorsomedial/central division (VMHdm/c) and ventromedial division (VMHvl). The PMN is divided into the dorsal nucleus (PMd) and ventral nucleus (PMv). Solid thin arrows indicate direct projections. Genetic markers in parentheses indicate specific populations of neurons within each nucleus that have been investigated with regard to regulation of the indicated social behavior.

hypothalamus functions 2.png

Human and animal sadness and animal separation-distress/GRIEF systems. Animal data comes from mapping of separation distress circuits with localized electrical stimulation in guinea pigs and human data from PET imaging of affective states by Damasio's group. AC, anterior cingulate; VS, ventral striatum; dPOA, dorsal preoptic area; BN, bed nucleus of the stria terminalis; DMT, dorsomedial thalamus; PAG, periaqueductal gray.

basic emotions Jaak Panksepp 4.jpg

[Petter]

red: parental care <--> sadness, separation-distress (crying)

yellow and orange: avoid a predator or an enemy <--> fear

green: approach a reward and defend a reward <--> positive excitement and negative excitement (i.e. anger)

blue: play, social dominance <--> happiness (laughing)

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hypothalamus functions.jpg

[Petter]

1. the need for pleasure and avoidance of pain <--> excitement (or euphoria), anger and fear

2. the need for control/orientation (achieve goals) <--> excitement (or euphoria), anger and fear

3. the need for attachment (safety needs: play/social grooming) <--> happiness and sadness

4. the need for self-esteem enhancement (social hierarchy: play/show off) <--> happiness and sadness

[Petter]

https://en.wikipedia.org/wiki/Hypothalamus

control/orientation (achieve goals) <--> tuberomammillary nucleus (attention, learning and memory)




https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4945459/

"The PMv is highly connected with the brain’s social networks (Canteras et al., 1992, Swanson, 2000, Cavalcante et al., 2014), and mapping studies using the immediate early gene Fos demonstrated that PMv neurons are activated in multiple social contexts (Cavalcante et al., 2006, Borelli et al., 2009, Motta et al., 2009, Donato et al., 2010, Donato et al., 2013)."

"Using a combination of molecular and genetic approaches we demonstrate that these PMv neurons regulate intruder-specific male social behavior..."

esteem needs <--> premammillary nucleus

[Petter]

1. the incongruity theory (see post #141 and #142)

2. transgression (something forbidden) ... e.g. breaking social norms

3. the superiority theory

A) Both illogical behavior and socially unacceptable behavior can be seen as inferior behavior.


B)

https://edition.cnn.com/2021/07/01/h...ess/index.html

"Laughter is thought to have evolved as a form of social bonding in animals and as a way to express playful intention. Many mammals laugh when they are tickled and when they engage in physical play."

This is probably a correct interpretation.

[Petter]

3. the need for attachment (safety needs: play/social grooming) <--> happiness and sadness

4. the need for self-esteem enhancement (social hierarchy: play/show off) <--> happiness and sadness pride and shame

These are not basic emotions. They depend on excitement, euphoria, dysphoria, anger and fear.

[Petter]

... and there are only two basic needs (3 and 4 are secondary needs)

[Petter]

https://www.findapsychologist.org/th...wilson-barlow/

Similarly, it is currently hypothesized that laughter stimulates the release of endorphins. Known as the brain’s natural opiate, endorphins can result in decreased pain and a sense of euphoria. Finally, laughter has been shown to decrease the secretion of the stress hormone, serum cortisol.




https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3267132/

Although laughter forms an important part of human non-verbal communication, it has received rather less attention than it deserves in both the experimental and the observational literatures. Relaxed social (Duchenne) laughter is associated with feelings of wellbeing and heightened affect, a proximate explanation for which might be the release of endorphins. We tested this hypothesis in a series of six experimental studies in both the laboratory (watching videos) and naturalistic contexts (watching stage performances), using change in pain threshold as an assay for endorphin release. The results show that pain thresholds are significantly higher after laughter than in the control condition. This pain-tolerance effect is due to laughter itself and not simply due to a change in positive affect. We suggest that laughter, through an endorphin-mediated opiate effect, may play a crucial role in social bonding.




https://www.medicalnewstoday.com/art...f-togetherness

The researchers found that the social laughter condition led to a significant increase in endorphin release in the thalamus, caudate nucleus, and anterior insula regions of the brain. These are brain regions that play a role in arousal and emotional awareness.

[...]

Other primates maintain social contacts by mutual grooming, which also induces endorphin release. This is however very time-consuming.




https://www.sciencedirect.com/scienc...9130222100056X

The social environment changes circulating hormone levels and expression of social behavior in animals. Social information is perceived by sensory systems, leading to cellular and molecular changes through neural processes. Peripheral reproductive hormone levels are regulated by activity in the hypothalamic-pituitary–gonadal (HPG) axis. Until the end of the last century, the neurochemical systems that convey social information to the HPG axis were not well understood. Gonadotropin-inhibitory hormone (GnIH) was the first hypothalamic neuropeptide shown to inhibit gonadotropin release, in 2000. GnIH is now regarded as a negative upstream regulator of the HPG axis, and it is becoming increasingly evident that it responds to social cues. In addition to controlling reproductive physiology, GnIH seems to modulate the reproductive behavior of animals. Here, we review studies investigating how GnIH neurons respond to social information and describe the mechanisms through which GnIH regulates social behavior.




https://www.reed.edu/biology/courses...mechanism.html

This notion that limbic system (thalamas, hypothalamas, hippocampus, amygdala, septuma and other associated strucutres) and motor cortical pathway together play a critical role in laughter is further supported by functional magnetic resonance imaging (FMRI) study conducted by Wattendorf et. al on human subjects and laughter.




https://en.wikipedia.org/wiki/Supraoptic_nucleus

The cell bodies produce the peptide hormone vasopressin, which is also known as anti-diuretic hormone (ADH), and the peptide hormone oxytocin.

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hypothalamus functions 3.jpg

hypothalamus and pituitary gland.jpg

[Petter]

laughter.png

hypothalamus happy sad.jpg

[Petter]

https://academic.oup.com/endo/articl...qac111/6648172

"Oxytocin promotes maternal nurturing and bonding, enhances social reward, and increases the salience of social stimuli. Vasopressin modulates social communication, social investigation, territorial behavior, and aggression, predominantly in males. Both peptides facilitate social memory and pair bonding behaviors in monogamous species."




https://era.ed.ac.uk/handle/1842/39044?show=full

"oxytocin and vasopressin neurons in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) are involved in the behavioural response to tickling"

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supraoptic nucleus and paraventricular nucleus.png

supraoptic nucleus and paraventricular nucleus 2.jpg

[Petter]

https://elifesciences.org/articles/69178

Dorsal premammillary projection to periaqueductal gray controls escape vigor from innate and conditioned threats.




https://pubmed.ncbi.nlm.nih.gov/10861538/

The dorsal premammillary nucleus (PMd) is thought to play a critical role for the expression of fear responses to environmental threats. We have reported previously that during an encounter with a predator the PMd presents an impressive increase in Fos levels and cell body-specific chemical lesions therein virtually eliminate the expression of escape and freezing responses.




https://www.ncbi.nlm.nih.gov/pmc/articles/PMC50283/

The dorsal premammillary nucleus: an unusual component of the mammillary body.

The results of anterograde and retrograde axonal transport experiments in the rat indicate that the dorsal premammillary nucleus (PMd) gives rise to a branched pathway ending in the anterior thalamic group and brainstem, like the medial and lateral mammillary nuclei. However, unlike these nuclei, the ascending PMd projection courses through and to the anterior hypothalamic nucleus, and the descending PMd projection ends in the periaqueductal gray, superior colliculus, and adjacent parts of the reticular formation. Also unlike the traditional mammillary nuclei, the PMd does not receive a direct input from the columns of the fornix; instead, it receives a bilateral input from the anterior hypothalamic nucleus, which in turn receives inputs from areas related to the prefrontal cortex, amygdala, and hippocampus. The results provide interesting perspectives on the organization of medial hypothalamic circuits underlying the goal-oriented behaviors associated with hunger, thirst, and reproduction.




https://pubmed.ncbi.nlm.nih.gov/16687159/

Although poorly investigated, previous studies have suggested that the PMV plays a role in aggressive and sexual behavior.




https://www.pnas.org/doi/10.1073/pnas.1305581110

These findings reveal an important role for the PMv in detecting the male intruder and how this nucleus modulates the network controlling maternal aggression.

The PMv is heavily targeted by the medial amygdalar nucleus...

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amygdala 2.jpg

amygdala 5.png

[Petter]

amygdala.jpg

amygdala 6.jpg

[Petter]

esteem needs <--> show off achievements (control/orientation)

1. play fighting: sports and games

2. art

3. work

[Petter]

https://www.momjunction.com/articles...ally_00642541/

"The fear of being away from the parents or caregiver is called separation anxiety. Although it is one of the developmental milestones, some babies can be extremely clingy and have sleep problems during this phase. Separation anxiety could cause a baby to cry when they wake up from sleep. If your baby requires co-sleeping, reassuring, feeding, or holding to fall asleep, they are not yet ready to sleep on their own."

I think this is sadness.

The other reasons for crying are different kinds of sensory/physical discomfort, which leads to distress/dysphoria (i.e. 'disliking'). So crying is not always caused by sadness.

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babies crying.jpg

[Petter]

The GRIEF/separation distress system

[This] system was initially called the PANIC system, but few understood the intent of that primary-process terminology, so we shifted to the more comprehensible tertiary-process term of GRIEF (highlighting once more terminological problems in emotion research: what are the differences between the tertiary-level emotions of bereavement, grief, and mourning, for instance?). In any event, young socially dependent animals have powerful emotional systems to solicit nurturance. They exhibit intense crying when lost, alerting caretakers to attend to their offspring. ESB mapping of this separation-distress system has highlighted circuitry running from dorsal PAG to anterior cingulate, and it is aroused by glutamate and CRF and inhibited by endogenous opioids, oxytocin, and prolactin - the major social-attachment, socialbonding chemistries of the mammalian brain. These neurochemicals are foundational for the secure attachments that are so essential for future mental health and happiness. It is still worth considering that panic attacks may reflect sudden endogenous spontaneous loss of feelings of security (acute separation-distress) rather than sudden FEAR. We predict that these circuits are tonically aroused during human grief and sadness, feelings that accompany low brain opioid activity.

GRIEF/sadness could be a basic emotion, though.

[Petter]

https://www.medicalnewstoday.com/art...iety-in-babies

"What causes separation anxiety in babies?

Separation anxiety occurs when babies begin to learn object permanence. Object permanence is the understanding that people and objects continue to exist, even when the baby cannot see them.

Babies begin to understand this when they are 6–12 months old. However, because they do not have an understanding of time, they do not know when their caregiver will come back. This causes them to become afraid and agitated."

[Petter]

dysphoria: increased DA (hedonic coldspot: 'disliking')

sadness: decreased DA ('wanting') and NA ---> temporary anhedonia and apathy

depression: decreased DA, NA and 5-HT (serotonin) ---> persistent sadness and feelings of worthlessness

[Petter]

Sadness could be the opposite of excitement.

basic emotions future and past.png

[Petter]

Distress could be the opposite of happiness.

happiness = relaxedness + play/laughing + euphoria

[Petter]

6 basic emotions: excitement, fear, euphoria, dysphoria, anger, sadness

anger <--> "the demand to fix it" (Silvan Tomkins)

sadness <--> hopelessness

[Petter]

sadness <--> hopelessness

... and meaninglessness

Wikipedia

The anterior cingulate cortex is central to the affective response of physical pain and is involved in the detection and interpretation of social pain such as threats, rejection, exclusion, loss, and negative evaluation of others. The anterior cingulate cortex is particularly active when the individual thinks negative thoughts about himself.

The anterior cingulate cortex is directly related to sadness.

[Petter]

separation distress <--> fear (not sadness)

[Petter]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4321627/

The core feature of separation anxiety is excessive distress when faced with actual or perceived separation from people to whom the individual has a strong emotional attachment. So far little is known about the neurobiological underpinnings of separation anxiety. Therefore, we investigated functional (amygdala responsiveness and functional connectivity during threat-related emotion processing) and structural (grey matter volume) imaging markers associated with separation anxiety as measured with the Relationship Scale Questionnaire in a large sample of healthy adults from the Münster Neuroimaging Cohort (N = 320). We used a robust emotional face-matching task and acquired high-resolution structural images for morphometric analyses using voxel-based morphometry. The main results were positive associations of separation anxiety scores with amygdala reactivity to emotional faces as well as increased amygdala grey matter volumes. A functional connectivity analysis revealed positive associations between separation anxiety and functional coupling of the amygdala with areas involved in visual processes and attention, including several occipital and somatosensory areas. Taken together, the results suggest a higher emotional involvement in subjects with separation anxiety while watching negative facial expressions, and potentially secondary neuro-structural adaptive processes. These results could help to understand and treat (adult) separation anxiety.

[Petter]

1. the need for pleasure (and avoidance of pain)

2. the need for control/orientation (achieve goals)

3. the need for attachment (safety needs: play/social grooming)

4. the need for self-esteem enhancement (social hierarchy: show off achievements)

1. blue

2. grey

3. green

4. red

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hypothalamus functions 12.jpg

[Petter]

excitement: high DA and NA

interest: medium DA and NA ... the default mode

sadness and boredom: low DA and NA

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sadness <--> anhedonia ("general boredom")

[Petter]

anger and fear: medium/high DA and NA

calmness: low DA and NA ... this is not an emotion

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https://pubmed.ncbi.nlm.nih.gov/30179855/

"Dopamine appears to mediate conditioned fear by acting at rostral levels of the brain and regulate unconditioned fear at the midbrain level."

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https://pubmed.ncbi.nlm.nih.gov/33885919/

"The results reinforce the importance of D2 receptors in fear conditioning and suggest that dopaminergic mechanisms mediated by D2 receptors are mainly involved in the expression rather than in the extinction of conditioned freezing."

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https://www.smh.com.au/national/dopa...12-gdicc5.html

"Dopamine, on the other hand, makes us excitable. When we lose our temper, it is dopamine, and adrenaline, that overwhelms us and triggers the fight-or-flight response that used to save us from sabre-tooth tigers and the like."

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https://www.sciencedirect.com/topics...y/noradrenalin

"Norepinephrine plays a role in vigilance and conditioned fear, and therefore should also modulate unconditioned fear."

[Petter]

excitement <--> a potential reward (pleasure)

fear <--> a potential punishment (pain)



euphoria <--> a reward

dysphoria <--> a punishment



anger <--> an obstacle, goal-blockage: hopefulness (high NA and low 5-HT)

sadness <--> an obstacle, goal-blockage: hopelessness (low NA and low 5-HT)

[Petter]

sadness.jpeg

serotonin 10.png

[Petter]

https://pubmed.ncbi.nlm.nih.gov/21144997/

Dopamine in motivational control: rewarding, aversive, and alerting

Midbrain dopamine neurons are well known for their strong responses to rewards and their critical role in positive motivation. It has become increasingly clear, however, that dopamine neurons also transmit signals related to salient but nonrewarding experiences such as aversive and alerting events. Here we review recent advances in understanding the reward and nonreward functions of dopamine. Based on this data, we propose that dopamine neurons come in multiple types that are connected with distinct brain networks and have distinct roles in motivational control. Some dopamine neurons encode motivational value, supporting brain networks for seeking, evaluation, and value learning. Others encode motivational salience, supporting brain networks for orienting, cognition, and general motivation. Both types of dopamine neurons are augmented by an alerting signal involved in rapid detection of potentially important sensory cues. We hypothesize that these dopaminergic pathways for value, salience, and alerting cooperate to support adaptive behavior.

[Petter]

serotonin 4.jpg

monoamine neurotransmitter 4.jpg

[Petter]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5332864/

Freeze for action: neurobiological mechanisms in animal and human freezing

There are many other hormones and peptides known to affect freezing, including progesterone, testosterone, oestrogen, oxytocin and vasopressin. Oxytocin may, for example, affect the shift from freezing to active defensive responses by acting on cholinergic transmission in the lateral CE of the amygdala and the ACC, but also by inhibiting vasopressin neurons in the medial CE that project to the vlPAG. These hormones and peptides also act on other neurotransmitter systems implicated in the expression of freezing, including gamma-aminobutyric acid (GABA) dopamine and serotonin. GABA tonically inhibits defensive behaviour in the amygdala, hypothalamus and the PAG, an effect opposed by excitatory amino acids. Serotonin release in the dlPAG and in the rostral ventrolateral medulla inhibits active fight-or-flight behaviours. Interestingly, there are indications that endogenous serotonin in these regions originates not only from the dorsal raphe nucleus but also from the vlPAG, suggesting an additional mechanism by which vlPAG activity can inhibit dlPAG-driven fight-or-flight reactions.

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fear <--> serotonin 1

sadness <--> serotonin 2

[Petter]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6043598/

Although anger and aggression have been researched since decades, there are still few studies on the neural functions that dissociate feelings of anger from the regulation of aggressive responses or reactive punishment behaviors. Anger and aggression are conceptually related, but anger does not always result in aggression. In fact, the emotion of anger, which is defined as a negative emotional response to goal-blockage and unfair behavior by others, is conceptually distinct from aggression, which is defined as an action intended to cause harm to another individual. Although aggression is often perceived as maladaptive, certain forms of aggression may actually serve evolutionary adaptive purposes, such as securing resources or defending against attacks.

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Aggression is caused by goal-blockage and unfair behavior is a combination of empathy (or a lack of empathy) and goal-blockage.

[Petter]

sadness <--> anhedonia ("general boredom")

happiness <--> "general excitement" (?) ... everything excites him/her

[Petter]

happiness and sadness <--> mood