Prefrontal Cortex Flashcards
What are the layers of cells in the prefrontal cortex?
Layer 2/3: Pyramidal
Layer4: input occurs, paravalbumin GABA, somatostatin GABA
Layer5: Thick tufted pyramidal (subcortical projection), Thin tufted pyramidal (cortical projection)
What are the afferent and efferent connections of the prefrontal cortex?
Afferent: Thalamic nuclei
Medio dorsal
Ventral anterior
anterior complex
Efferent: Medio-dorsal thalamus Basal ganglia hippocampus association cortices amygdala hypothalamus cerebellum Brain stem
What role does dopamine projections play in the prefrontal cortex?
Dopamine neurons in midbrain ventral tegmental ares project to PFC and synapse on both GABAergic interneurons and pyramidal neurons in layers 4 and 5.
Important in signalling reward of goal directed behaviours
Explain the effects high/low dopamine release has on PFC?
High: inhibits cortical inputs onto basal dendrites, allowing thalamic inputs on apical dendrites to predominate
Low: allows cortical inputs to predominate (more inhibition of pyramidal cells)
Describe three other PFC NT inputs
Noradrenaline: from locus coeruleus, layers 2 and 5
ACh: from basal forebrain, mainly layers 3 and 6
5HT: from brainstem, layers 3 and 4
Describe what occurs with a PFC orbital lesion?
Impulsive irritable hyperactive High risk behaviour can't pay attention Preservation
Describe what occurs with a medial PFC lesion?
Loss of general motility
Loss of spontaneity
Apathy
Summary: dampening of emotional response
Describe what occurs with a medial PFC lesion?
Cognitive deficits (selective attention, working memory, language)
Depression
Apathy
Decrease in organisation
Describe the model of short term memory and how the prefrontal cortex influences this.
See picture in notes (last page)
List negatives the prefrontal cortex
depression, anxiety Early onset of AD ASD attention deficits, hyperactivity PTSD OCD Addiction
