GABA neurons in the substantia nigra pars reticulata receive input from GABAergic fibers originating in the forebrain. The role of dopaminergic D1 receptors located on these fibers was investigated using tight-seal whole-cell recordings from visually identified pars reticulata neurons of rat substantia nigra slices. Nondopaminergic pars reticulata neurons were characterized by their electrophys...

Analysis of an acid extract of the striatum of the rhesus monkey revealed that the molar ratio of dynorphin A(1-8)-sized material and dynorphin (A(1-17)-sized material is approximately 1:1. In addition, the molar ratios of the dynorphin A-related end products to both dynorphin B(1-13)-sized material and alpha-neo-endorphin-sized material were approximately 1:1. Fractionation of an acid extract ...

OBJECTIVE The overall goal of this study was to evaluate the usability of the susceptibility weighted imaging (SWI) in (1) assessment of iron deposition to enhance our ability to detect PD in the early phase and (2) in estimation of the degree of PD. PATIENTS AND METHODS SWI scans were carried out in 54 patients with PD (18 patients with the Hoehn-Yahr scale < 1.5 and 36 patients with the Hoe...

Dopamine content in the basal ganglia is strongly associated with the degree of dopaminergic neuron loss in the substantia nigra pars compacta. Symptoms of Parkinson's disease might not arise until more than 50% of the substantia nigra pars compacta is lost and the dopamine content in the basal ganglia is reduced by more than 80%. Greater diagnostic sensitivity and specificity would allow earli...

Previous studies have indicated that the substantia nigra contains the highest concentration of substance P-like immunoreactivity (SPLI) in the brain. Paradoxically, it also appears to contain one of the lowest concentrations of substance P receptors in the brain. One possibility is that the massive amount of SPLI blocks the binding of the radioligand to the substance P receptor and/or "down-re...

The ventral striatum is considered an interface between limbic and motor systems. We followed the orbital and medial prefrontal circuit through the monkey basal ganglia by analyzing the projection from this cortical area to the ventral striatum and the representation of orbitofrontal cortex via the striatum, in the globus pallidus and substantia nigra. Following injections of Lucifer yellow and...

One objective of modern neuroimaging is to identify markers that can aid in diagnosis, disease progression monitoring and long-term drug impact analysis. In this study, Parkinson-associated physiopathological modifications were characterized in six subcortical structures by simultaneously measuring quantitative magnetic resonance parameters sensitive to complementary tissue characteristics (i.e...

Automated segmentation of anatomical sub-regions with high precision has become a necessity to enable the quantification and characterization cells/ tissues in histology images. An automated model do this task is currently unavailable. One area brain which requires precise sub-region downstream analysis Substantia Nigra (SN). The loss dopaminergic (DA) neurons SN primary endpoint for majority P...

INTRODUCTION Parkinson's disease (PD) is characterized by the accumulation of abnormal α-synuclein in selected regions of the brain following a gradient of severity with disease progression. Whether this is accompanied by globally altered protein synthesis is poorly documented. The present study was carried out in PD stages 1-6 of Braak and middle-aged (MA) individuals without alterations in br...

Parkinson's disease is a neurodegenerative disorder of the substantia nigra accompanied by the depletion of dopamine levels. Symptoms of Parkinson's disease involve motor disorders, including dysphagia and aspiration. In this study, rats were injected with 6-hydroxydopamine (6-OHDA) in order to assess the eating disorder and evaluate the effect of transplantation of neural progenitor cells (NPC...