TY - JOUR
T1 - Anatomical and electrophysiological characterization of presumed dopamine-containing neurons within the supramammillary region of the rat
AU - Shepard, Paul D.
AU - Mihailoff, Gregory A.
AU - German, Dwight C.
PY - 1988/3
Y1 - 1988/3
N2 - A combination of immunocytochemical, electrophysiological and pharmacological techniques were employed to study the properties of neurons within the supramammillary (SUM) complex of the rat. The SUM region contains a small, but dense, population of tyrosine hydroxylase immunoreactive neurons. Following injection of the orthograde neuroanatomical tracer, Phaseolus Vulgaris leucoagglutinin, into the SUM region, heavy termainal labeling was observed in the lateral septal nucleus, diagonal band of Broca and bed nucleus of the stria terminalis. The electrophysiological and pharmacological properties of antidromically-activated SUM neurons revealed evidence of two neuronal populations. Both groups of neurons exhibited long duration action potentials (>2 msec) and slow conduction velocities (<0.5 m/sec). However, cells in one group were characterized by slow and erratic firing rates and insensitivity to dopamine (DA) autoreceptor agonists. Cells in the other group typically exhibited no spontaneous activity but could be induced to discharge by iontophoretic application of glutamate. These latter cells were sensitive to DA autoreceptor stimulation. Of the two populations of mammilloseptal SUM neurons, the silent population exhibited several properties similar to those of midbrain DA neurons.
AB - A combination of immunocytochemical, electrophysiological and pharmacological techniques were employed to study the properties of neurons within the supramammillary (SUM) complex of the rat. The SUM region contains a small, but dense, population of tyrosine hydroxylase immunoreactive neurons. Following injection of the orthograde neuroanatomical tracer, Phaseolus Vulgaris leucoagglutinin, into the SUM region, heavy termainal labeling was observed in the lateral septal nucleus, diagonal band of Broca and bed nucleus of the stria terminalis. The electrophysiological and pharmacological properties of antidromically-activated SUM neurons revealed evidence of two neuronal populations. Both groups of neurons exhibited long duration action potentials (>2 msec) and slow conduction velocities (<0.5 m/sec). However, cells in one group were characterized by slow and erratic firing rates and insensitivity to dopamine (DA) autoreceptor agonists. Cells in the other group typically exhibited no spontaneous activity but could be induced to discharge by iontophoretic application of glutamate. These latter cells were sensitive to DA autoreceptor stimulation. Of the two populations of mammilloseptal SUM neurons, the silent population exhibited several properties similar to those of midbrain DA neurons.
KW - Dopamine
KW - Electrophysiology
KW - Lateral septal nucleus
KW - Phaseolus
KW - Supramammillary nucleus
KW - Tyrosine hydroxylase immunohistochemistry
KW - Vulgaris leucoagglutinin
UR - http://www.scopus.com/inward/record.url?scp=0024156814&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0024156814&partnerID=8YFLogxK
U2 - 10.1016/0361-9230(88)90060-3
DO - 10.1016/0361-9230(88)90060-3
M3 - Article
C2 - 2896530
AN - SCOPUS:0024156814
SN - 0361-9230
VL - 20
SP - 307
EP - 314
JO - Brain Research Bulletin
JF - Brain Research Bulletin
IS - 3
ER -