Neurophysiology of limbic system pathways in the rat: projections from the amygdala to the entorhinal cortex.
We studied the responses of rat entorhinal neurons to electrical stimulation of the amygdala. Four main results were obtained: (1) excitatory postsynaptic potentials were recorded in entorhinal neurons in response to electrical stimulation of the amygdala. Cells in layers II, III and V of the entorhinal cortex were responsive. (2) Excitatory responses were followed by inhibitory postsynaptic potentials. (3) Frequency potentiation of both excitatory and inhibitory responses was observed when 10/s stimulation was used. (4) Three amygdala neurons were antidromically activated by entorhinal stimulation; and two layer II entorhinal cells that were excited by amygdala stimulation were also antidromically activated by dentate gyrus stimulation. These results provide evidence for a monosynaptic, excitatory projection from the amygdala to the entorhinal cortex. In addition, the data indicate that amygdala neurons are only one synapse removed from the excitation of dentate gyrus granule cells.
Finch
D M
DM
Wong
E E
EE
Derian
E L
EL
Chen
X H
XH
Nowlin-Finch
N L
NL
Brothers
L A
LA
D000200:Action Potentials; D000679:Amygdala / Q000033:anatomy & histology / Q000502:physiology*; D000818:Animals; D001370:Axonal Transport; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D004525:Efferent Pathways / Q000502:physiology; D004558:Electric Stimulation; D005071:Evoked Potentials; D008032:Limbic System / Q000033:anatomy & histology / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013569:Synapses / Q000502:physiology