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The deep mesencephalic nucleus as an output center of basal ganglia: Morphological and electrophysiological similarities with the substantia nigra
Author(s) -
Rodríguez Manuel,
Abdala Patricio,
BarrosoChinea Pedro,
GonzálezHernández Tomas
Publication year - 2001
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.1299
Subject(s) - neuroscience , superior colliculus , substantia nigra , midbrain , biology , pedunculopontine tegmental nucleus , pars reticulata , basal ganglia , tegmentum , thalamus , striatum , periaqueductal gray , electrophysiology , inferior colliculus , pedunculopontine nucleus , midbrain reticular formation , anatomy , medium spiny neuron , ventral tegmental area , brainstem , nucleus , dopamine , central nervous system , deep brain stimulation , dopaminergic , medicine , disease , parkinson's disease
The deep mesencephalic nucleus (DMN) is a large midbrain reticular region between the superior colliculus, the substantia nigra compacta, the periaqueductal gray, and the medial geniculate body. Although some data suggest that it is involved in nociception and visceral control, its functions remain unclear. In the present study, by using morphological (combination of anterograde and retrograde tracers with immunocytochemistry and in situ hibrydization) and electrophysiological (firing activity and transynaptic response to striatal stimulation) methods, we show that a subpopulation of DMN cells shares many morphological and electrophysiological characteristics with those of the substantia nigra reticulata (SNR). These similarities include the following: 1) firing rate, firing pattern, and conduction velocity; 2) expression of GAD65, GAD67, and PV; 3) excitatory and inhibitory inputs from the striatum; and 4) projections to the ventral thalamus, superior colliculus, and pedunculopontine tegmental nucleus. Some differences were also found. In comparison with SN, DMN cells and striatal afferents are more sparsely distributed and they show conspicuous contralateral projections to the thalamus and superior colliculus. This suggests that, similarly to the SNR, the DMN acts as an output center of basal ganglia and probably facilitates the inter‐hemispheric regulation of these centers. J. Comp. Neurol. 438:12–31, 2001. © 2001 Wiley‐Liss, Inc.