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.
D M
DM
Finch
E E
EE
Wong
E L
EL
Derian
X H
XH
Chen
N L
NL
Nowlin-Finch
L A
LA
Brothers
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