pfc and subcortical pleasure/reward circuit Flashcards
What are the projections to the PFC?
Remember: Bx2, Ax2, Hx2, C, O, M
B = Brainstem B = Basal Ganglia A = Amygdala A = Association cortices H = Hippocampus H = Hypothalamus C = Cerebellum O = Other PFC Areas M = Medial Dorsal Thalamus
Lateral PFC
Temporal organisation of speech, behaviour and reasoning (rbs)
What is the function and the inputs/outputs of the VTA?
Function: is to differentiate between a positive and negative input. Increased DA firing if positive. GABA and GLU modulates the dopamine firing in response to stimulus.
Inputs: PHAN PFC Hippocampus Amygdala Nucleus Accumbens
Outputs: PHBBSV PFC Hypothalamus Brainstem BNST Substantia Nigra Ventral Pallidum
What is the function of the NAc and its associated inputs and outputs?
Function: To increase DA and activity in relation to reward stimulus ie. Sensory (increase), Abstract(restricts), or Anticipatory(increases dependent on magnitude, effort and other factors influencing reward).
Inputs: PHATV(TA) P - PFC (GLU) H - Hippocampus A - Amygdala T - Thalamus (GLU) V- VTA
Outputs: Very Small Boys’ Penis / Very High Nuts
V - VTA S - SN B - BNST P - PPT V - Ventral Pallidum H - Hypothalamus N - Nucleus Basalis
What is the function of the Ventral Pallidum and what are its inputs and outputs?
Function: is to direct and learn performance of reward incentive behaviour –> the motor output to achieve the reward.
Inputs: BASAL GANGLIA abbreviations (VVSSP) VTA VS - Ventral Striatum SN STN PPT
Outputs: HELMET (SAM) T - Thalamus L - Lateral Habenula D - Dorsal Pallidum H - Hypothalamus
What is the function of the Lateral Habenula and its inputs and outputs?
Function: Anti-reward system; the negative regulation of DA and Serotonin release
Inputs: PAHB (PUB) P - PFC A - Amygdala H - Hypothalamus B - Basal Ganglia
Outputs: Very Bad
V - VTA
B - Brainstem nuclei
What is the function of the lateral hypothalamus and its inputs and outputs?
Functions: Reward processing and addiction (conditioned place preference)
Input: LITERALLY BS
Lateral septum
BNST
Output: V
V - VTA
What is the function of the Medial Dorsal Thalamus and its inputs and outputs?
Functions: relay centre (gateway into PFC)
Input: OF COURSE ITS LATERAL; Taking a NAP at CENTRAL; BOTH BRAINSTEM
(L) - OFC
(C) - Nucleus Accumbens (NAc); Amygdala, PFC
(Both) - Brainstem nuclei
Output: gateway to PFC
PFC
What is the function of the Cortices in the PFC and their projections to reward/pleasure structures (ie. sensory vs. abstract)?
Functions: the projections in the PFC allow for pleasure/rewards processing dependent on stimulus type (sensory or abstract).
SENSORY:
- Posterior OFC
- vmPFC
ABSTRACT:
- Anterior OFC
- mvPFC (medial)
- dPFC and dACC –> reward comparison
- mPFC –> reward tracking (size, value)
What type of cells are found in PFC layer 4?
Granular cells (high density)
Parvalbumin interneurons (GABAergic markers)
Somatostatin interneurons (GABAergic markers)
What are the 3 thalamic nuclei projections into the PFC and the outputs of PFC
INPUT PROJECTIONS:
Ventroanterior
Medialdorsal
Anterior complex
OUTPUT: (BHA)x2 COM B - Brainstem B - Basal Ganglia A - Amygdala A - Association Cortices H - Hypothalamus H - Hippocampus C - Cerebellum O - Other premotor areas M - Medial Dorsal Thalamus
Explain Dopaminergic gated inputs.
DA leads to goal directed behaviour
Dopaminergic neurons in VTA project into layer 4 and 5 of PFC and synapse with GABAergic interneurons (parvalbumin/somatostatin) and pyramidal neurons.
High DA inhibits cortical input to BASAL dendrites, allowing thalamic dominance on APICAL dendrites
Low DA favours the BASAL dendrite input allowing cortical input to dominate
What are the other neurotransmitters inputs in PFC aside from DA?
Ach
- layers 3 to 6
- Basal Forebrain to ORBITAL, MEDIAL AND LATERAL PFC
!! and Lateral PFC receives Ach from brainstem !!
NE
- layers 2 to 5
- Locus coeruleus to ORBITAL, MEDIAL AND LATERAL PFC
SEROTONIN
- layers 3 and 4
- Brainstem to ORBITAL, MEDIAL AND LATERAL PFC
Development of PFC
Is a later developer in brain
1-2yrs: lengthening of dendrites and branching, and cell volume growth
16yrs: Highest density of synaptic formation reached
30+yrs: Neurotransmitter presence peaks
!! myelination takes many years !!
What are the sections of PFC, their location, and general function?
Orbtial PFC: Ventral-medial region
- emotional behaviour
Medial PFC: Medial-frontal lobe along longitudinal fissure
- emotional behaviour
Lateral PFC: Dorsolateral region
- temporal organisation of speech, behaviour and reasoning
