Neurons of the Basal Ganglia of the Human Brain (striatum and basolateral amygdala) Expressing the Enzyme NADPH-d

Abstract

Types of NADPH-d+ neurons (Vincent et al., 1983) were identified in the striatum and basolateral nuclei of the amygdala; striocortical neurons were detected in the striatum using the DiI marker (Belichenko and Dahlström, 1995). NADPH-d+ cells were numerous. Staining of these cells and all their processes, along with our previous studies of the neurons in these formations in the human brain using the Golgi method, allowed us to identify their shapes and identify them as sparsely or extensively branched cells. The main efferent neurons of the striatum and basolateral amygdala (extensively branched medium spiny cells and bushy spiny cells respectively) and their extensively branched interneurons did not contain NADPH-d. Efferent NADPH-d+ neurons included reticular, sparsely branched cells with long dendrites, which were the most numerous cells in both formations, as well as occasional large multipolar branched neurons; the striatum also contained numerous sparsely branched short-dendrite cells (a neuron type most represented in the brainstem and especially the reticular formation). Projections of reticular cells from the striatum to the cortex were demonstrated. NADPH-d+ interneurons were sparsely branched: in the striatum, these were slender, long-dendrite, bipolar cells (numerous), ordinary bipolar cells, twisted and large dendrite-poor cells; the amygdala contained the same bipolar cells along with radial neurons. Thus, NADPH-d+ neurons in these formations were more ancient, i.e., structurally less complex, cell types.

Nitric Oxide Modulation of the Basal Ganglia Circuitry: Therapeutic Implication for Parkinson's Disease and Other Motor Disorders

“…Although NOS neurons are present throughout all BG nuclei and in other regions involved in motor control such as the motor cortices and the PPT, their concentration varies significantly [5,[22][23][24][25][26][27][28]. For example, in comparison with other brain centers, the SNc may be considered a rather NOS cell-poor nucleus [29,30].…”

“…This efferent nitrergic cell was demonstrated to project to the insular cortex. Thus, at least some of the NOS reticular neurons of the human striatum have direct cortical projections, though the existence of their axon collaterals in striatal tissues close to the maternal cells also demonstrates that they influence surrounding cells [26]. Moreover, the matrix is the striatal compartment with the densest NOS neuronal population that tends to be located at the boundaries between the striosomes and the matrix, as well as at the boundaries between the core and the peripheral region of the striosomes [41].…”

Nitric Oxide Modulation of the Dopaminergic Nigrostriatal System: Focus on Nicotine Action

“…The pharmacological blocking of nNOS decreases locomotion and induces catalepsy in different animal species [see Del Bel et al (2007) for a review]. Although NOS neurons are present throughout all basal ganglia nuclei and in other regions involved in motor control such as the motor cortices and the pedunculopontine tegmental nucleus (PPTg), their concentration varies significantly (Bredt et al 1990;Del Bel et al 2007;Egberongbe et al 1994;Eve et al 1998;Garthwaite and Boulton 1995;Leontovich et al 2004;Nisbet et al 1994;Vincent and Kimura 1992).…”

“…The NOS expression in the striatum has been more extensively studied (Bernácer et al 2005;Egberongbe et al 1994;Eve et al 1998;Govsa and Kayalioglu 1999;Johannes et al 2003;Leontovich et al 2004;Nisbet et al 1994;Vincent and Kimura 1992). NOS neurons are one type of the four different classes of interneurons present in the striatum, and in the human they populate the entire striatum, including the tail and head of the caudate nucleus.…”

“…This efferent nitrergic cell was demonstrated to project to the insular cortex. Thus, at least some of the NOS reticular neurons of the human striatum have direct cortical projections, though the existence of their axon collaterals in striatal tissues close to the maternal cells also demonstrates that they influence surrounding cells (Leontovich et al 2004). Moreover, the matrix is the striatal compartment with the densest NOS neuronal population that tends to be located at the boundaries between the striosomes and the matrix, as well as at the boundaries between the core and the peripheral region of the striosomes (Bernácer et al 2005).…”