Neuronal density and proportion of interneurons in the associative, sensorimotor and limbic human striatum

Abstract

The striatum (caudate nucleus, putamen and nucleus accumbens) is the main input structure of the basal ganglia. It receives cortical projections from the vast majority of the cortex, as well as from other subcortical structures such as the thalamus and amygdala. Its role in planning, preparation and execution of voluntary movements is known to be fine-tuned by the interaction between projection neurons and interneurons. Since the 1990s, it has been accepted that the proportion of interneurons increases phylogenetically, being about 5% in rodents and 26% in humans. However, these data have not been confirmed with unbiased techniques, such as stereology. In the present report, we have divided the human striatum into functional territories (associative, sensorimotor and limbic) and we have quantified the numerical density of all striatal neurons (using Nissl staining) in each area. Taking into account our past research on the estimation of striatal interneurons, we have calculated the proportion of interneurons in each territory. This value was on average 17.1% for the whole striatum, although interneurons were more abundant in the associative (21.9%) than in the sensorimotor (12.8%) and limbic (11.1%) aspects. Therefore, we demonstrate with unbiased stereology that the overall proportion of striatal interneurons is slightly lower than that reported in previous studies, and that it varies in the functional territories of this structure.

Transcriptional and anatomical diversity of medium spiny neurons in the primate striatum

“…17 We found that our neuronal nuclei samples contained approximately 85% MSNs and 15% interneurons; this is a higher proportion of interneurons than was recovered from single-cell analysis of rodent striatum 17 but consistent with counts made in humans. 53 A novel and relatively rare MSN type has been recently documented and variously described as eccentric SPNs, 16,17 Pcdh8-MSNs, 13 and D1H. 15 Both D1/D2 hybrids and D1-NUDAP neurons shared some characteristics with this novel cell type.…”

Neuron types in the primate striatum: Stereological analysis of projection neurons and interneurons in control and parkinsonian monkeys

“…In conclusion, numerical densities per volume, corrected for Z-axis shrinkage, were calculated with the following equation [51]:…”

Role of Lipid Peroxidation Process in Neurodegenerative Disorders

“…Genetically, it affects the 4th chromosomal gene; huntingtin (HTT) protein mutation and misfolding. The main area of the brain is affection in caudate; putamen nucleous; globus pallidus; and nucleus accumbens leads to cause the atrophy of brain via the neurodegenerative process [32,72]. The microscopical observation revealed that small spiny neurons of the caudate and putamen cause the astrocytosis.…”

“…The chronic event of cellular neurodegenerative process enhances the neuronal oxidative stress with an accumulation of free radicals and LPO process [73]. During the early stage of LPO process; neuronal cells losses the cell contents; shrinkage of caudate nucleolus; shrinkage and dilatation of the anterior horns of lateral ventricles [45,72]. Moreover, LPO process enhances the alteration of various neurotransmitters such as a gamma aminobutyric acid (GABA); acetylcholine; and substance P [74,75].…”