Mood Disorders I Flashcards
Physiological correlates of fear (feelings)
Heart and respiratory rate Cortisol and adrenaline Blood flow Analgesia Facial muscles Attention focused on perceived threat Emotions
Feelings are…
mental experiences that accompany a change in body state
Feelings allows…
a glimpse into ongoing homeostatic regulation
Feelings directly portray…
the advantageous or disadvantageous nature of a psychological situation, and facilitate learning of the conditions causing the imbalance and respective corrections
Emotions
An action programme triggered by external stimuli
Example of emotions
joy, fear, etc.
Drive
action programme to satisfy an instinctual physiological need
Drive examples
hunger or thirst
ex. high osmolarity –> dry mouth –> thirst
2 action programs
drive and emotion
Interoception
notice change in internal enviro
Exteroception
notice change in external enviro
e. by 5 senses
Nuclei involved in generating feelings
internal mileu –> lamina 1 pathway to homeostatic centres (NTS, PBN, PAG) –> thalamus –> cortex (esp. insula)
Viscera –> Vagus nerve –> NTS –> PBN, PAG, hypothalamus –> insula
Pathway for feelings–from viscera
Viscera –> Vagus nerve –> NTS –> PBN, PAG, hypothalamus –> insula
Pathway for feelings–for internal stimuli
internal mileu –> lamina 1 pathway to homeostatic centres (NTS, PBN, PAG) –> thalamus –> cortex (esp. insula)
Mood
stable and constant, not linked to speicific circumstances
Feelings
Reactive, breif, intense and circumscribed to a specific environmental event
Difference b/t feelings and mood
feeling = short term, event-related mood= long term, un-related to events
Dysregualtion of feeligs leads to
emotional arousal and exaggerated effects
ex. fear becomes anxiety (disregulated fear)
Dyregulation of mood leads to
chornic, sustained negative mood
pervasive sadness and anhedonia
Depression (defintion)
Unpleasant or dysphoric mood present most of the day, most days
- anhedonia
- more prevalent in women
- in response to life events but also has genetic and other factors
Depression is a mood disorder comprised of….
• Sadness • Loss of interest • Anhedonia • Lack of appetite • Feelings of guilt • Low self-esteem • Sleep disturbances • Feelings of tiredness • Poor concentration Transient and mild conditions of low mood to severe psychiatric disorder
DSM criteria for depression
Both of: • Depressed mood • Loss of interest Plus 4 of the following: - Altered Appetite - Altered Weight - Altered Sleep - Altered Psychomotor activity - Decreased energy - feeling Worthlessness - feeling Guilty - Difficulty Thinking - Difficulty Concentrating - Difficulty Making decisiones - Recurrent thoughts of death - Suicidal ideation
Etiology of depression
- Biogenic amine hypothesis
- Endocrine factors
- Environmental factor
- Immunologic factors
- Genetic factors
- Neurogenesis
What started the biogenic amine hypothesis
in 50s Noted that:
Drugs that depleted catecholamines –> depression like effects (reserpine)
Drugs that inhibited MAO and therefore increase catecholamines –> increased mood
NE (receptor numbers and types)
9 receptors
2 classes: alpha and beta
Coupled to G protein
NE roles
- Modulates PFC function
- Working memory processing
- Behaviour and attention
- Acquisition of emotionallyarousing memories
NE cell bodies and projection
cell bodies in LC or lateral trigeminal area
Project to : thalamus, hypothalamus, and cortex
5HT (receptors numbers and types)
14 5-HT receptors
classified in 7 types
mostly coupled to G-proteins
Altered binding potentional of ____ and distrubition of ___ in _________ in depression
5HT1a; 5HT1b; in cingulate, PFC, hippocampus
5HT involved in
stress repsonse
involved in everything but responsible for nothing
5HT cell bodies and projection locations
Bodies in rostral raphe nuclei or caudal raphe nuceli
project to amygdala, hippocampus, NAc, etc.
DA receptor numbers and classes
5 DA receptors
classified in 2 types
mostly coupled to G-proteins
DA has roles in
- Reward and motivation
- Working memory
- Attention
DA cell bodies in the
VTA and substantia nigra
Substantia nigra and DA
degeneration of substantia nigra –> PD
important for voluntary action
VTA and DA
axons to NAc and PFC
reward, motication, working memory and attention