Health & Environmental Research Online (HERO)


Print Feedback Export to File
561417 
Journal Article 
Amygdala input monosynaptically innervates parvalbumin immunoreactive local circuit neurons in rat medial prefrontal cortex 
Gabbott, PLA; Warner, TA; Busby, SJ 
2006 
1 
Neuroscience
ISSN: 0306-4522
EISSN: 1873-7544 
139 
3 
1039-1048 
The projection from the basolateral nucleus of the amygdala (BLA) conveys information about the affective significance of sensory stimuli to the medial prefrontal cortex (mPFC). By using an anterograde tract-tracing procedure combined with immunocytochemistry and correlated light/electron microscopical examination, labeled BLA afferents to layers 2-6 of the rat mPFC are shown to establish asymmetrical synaptic contacts, not only with dendritic spines (approximately 95.7% of targets innervated), but also with the aspiny dendritic shafts and somata of multipolar parvalbumin immunopositive (PV+) neurons. A population of PV- dendritic shafts was also innervated. Labeled BLA synaptic input to identified PV+ structures occurred in layers 2-6 of mPFC. The results indicate that labeled BLA afferents predominantly contact the spiny processes of presumed pyramidal cells and also provide a direct and specific innervation to a sub-population of local circuit neurons in mPFC containing PV. Since PV+ cells include two significant classes of fast-spiking GABAergic inhibitory interneuron (basket and axo-axonic cells), these novel observations indicate that the amygdalocortical pathway in the rat has the ability to directly influence functionally strategic [`]feed-forward' inhibitory mechanisms at the first stage of processing amygdalocortical information. 
amygdalocortical afferents; local circuit neurons; disynaptic GABAegic feed-forward inhibition; pyramidal cell activity