We investigated the distribution of neurons in the substantia nigra pars reticulata (SNr) which received cortical input. The activities of single SNr neurons were studied extracellulary in awake monkeys. SNr neurons showed excitatory and/or inhibitory responses to cortical stimulation. These responses were considered to be mediated by the subthalamic nucleus and striatum, respectively. The neurons receiving inhibitory input from the motor, premotor and supplementary motor areas (Motor-related cortical areas) were located in the lateral part of the SNr, whereas those with input from the medial, dorsal and orbital areas of the prefrontal cortex (PFmdo) were frequently found in the rostro-medial part of this nucleus. SNr neurons with inhibitory input from the ventral periprincipal area (PSv) were mainly distributed in the intermedio-lateral portion, with some degree of overlap with input from other cortical areas. The distribution of the excitatory input was almost similar to that of inhibitory one, but the excitatory input from the PSv was much stronger than that from the PFmdo. Some SNr neurons receiving cortical input were proved to project to the thalamus. Our results support the existence of several parallel organization of the cortico-basal ganglia loop circuits [G.E. Alexander, M.R. DeLong, P.L. Strick, Parallel organization of functionally segregated circuits linking basal ganglia and cortex, Ann. Rev. Neurosci., 9, 1986, pp. 357-381.], but interaction between the loops can not be ignored.
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http://dx.doi.org/10.1016/s0006-8993(97)01332-2 | DOI Listing |
Neuron
January 2025
Department of Pharmacology and Department of Pharmacy of the Second Affiliated Hospital, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou 310058, China. Electronic address:
Attention deficit hyperactivity disorder (ADHD), affecting 4% of the population, is characterized by inattention, hyperactivity, and impulsivity; however, its neurophysiological mechanisms remain unclear. Here, we discovered that deficiency of histamine H receptor (HR) in parvalbumin-positive neurons in substantia nigra pars recticulata (PV) attenuates PV neuronal activity and induces hyperactivity, impulsivity, and inattention in mice. Moreover, decreased HR expression was observed in PV in patients with ADHD symptoms and dopamine-transporter-deficient mice, whose behavioral phenotypes were alleviated by HR agonist treatment.
View Article and Find Full Text PDFbioRxiv
December 2024
Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
The basal ganglia play a crucial role in action selection by facilitating desired movements and suppressing unwanted ones. The substantia nigra pars reticulata (SNr), a key output nucleus, facilitates movement through disinhibition of the superior colliculus (SC). However, its role in action suppression, particularly in primates, remains less clear.
View Article and Find Full Text PDFNat Commun
January 2025
School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA.
Energy efficiency in computation is ultimately limited by noise, with quantum limits setting the fundamental noise floor. Analog physical neural networks hold promise for improved energy efficiency compared to digital electronic neural networks. However, they are typically operated in a relatively high-power regime so that the signal-to-noise ratio (SNR) is large (>10), and the noise can be treated as a perturbation.
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
December 2024
Department of Biological Sciences, Hunter College, City University of New York, New York, NY 10065, USA.
Background: Spatial-temporal control of mRNA translation in dendrites is important for synaptic plasticity. In response to pre-synaptic stimuli, local mRNA translation can be rapidly triggered near stimulated synapses to supply the necessary proteins for synapse maturation or elimination, and 3' untranslated regions (UTRs) are responsible for proper localization of mRNAs in dendrites. Although is a robust technique for analyzing RNA localization in fixed neurons, live-cell imaging of RNA dynamics remains challenging.
View Article and Find Full Text PDFJ Electromyogr Kinesiol
February 2025
School of Information Science and Technology, Dalian Maritime University, Linghai Road 1, Dalian, Liaoning Province 116026, China. Electronic address:
This study proposed a U-Net based partial convolutional time-domain model for a real-time high-density surface electromyography (HD-sEMG) decomposition. The model combines U-Net and a separation block containing partial convolution, aiming to efficiently identify motor units (MUs) without preprocessing. The proposed U-Net based network was trained by the HD-sEMG signals with innervation pulse trains (IPTs) labels, and the results are compared between different step sizes, noises, and model structures under the sliding time window with 120 sampling points.
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