A primary function of the midbrain stimulus selection network is to compute the highest-priority location for attention and gaze. Here we report the contribution of a specific cholinergic circuit to this computation. We functionally disconnected the tegmental cholinergic nucleus isthmi pars parvocellularis (Ipc) from the optic tectum (OT) in barn owls by reversibly blocking excitatory transmission in the Ipc. Focal blockade in the Ipc decreases the gain and spatial discrimination of OT units specifically for the locations represented by the visual receptive fields (VRFs) of the disconnected Ipc units, and causes OT VRFs to shift away from that location. The results demonstrate mechanisms by which this cholinergic circuit controls bottom-up stimulus competition and by which top-down signals can bias this competition, and they establish causal linkages between a particular circuit, gain control and dynamic shifts of VRFs. This circuit may perform the same function in all vertebrate species.
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http://dx.doi.org/10.1038/ncomms13472 | DOI Listing |
Br J Pharmacol
January 2025
Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy.
Background And Purpose: Inflammatory bowel disease (IBD) patients display genetic polymorphisms in toll-like receptor 4 (TLR4) genes, contributing to dysregulate enteric nervous system (ENS) circuits with increased levels of 5-HT and alteration of the neuroimmune crosstalk. In this study, we investigated the impact of TLR4 signalling on mouse ENS dysfunction caused by dextran sulphate sodium (DSS)-induced ileitis.
Experimental Approach: Male C57BL/6J (wild-type [WT]) and TLR4 mice (10 ± 2 weeks old) received 2% DSS in drinking water for 5 days and then were switched to 3-day regular drinking water.
J Neurosci
January 2025
Laboratory on Neurobiology of Compulsive Behaviors, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, 20892. USA.
Dopamine critically regulates neuronal excitability and promotes synaptic plasticity in the striatum, thereby shaping network connectivity and influencing behavior. These functions establish dopamine as a key neuromodulator, whose release properties have been well-studied in rodents but remain understudied in nonhuman primates. This study aims to close this gap by investigating the properties of dopamine release in macaque striatum and comparing/contrasting them to better-characterized mouse striatum, using ex vivo brain slices from male and female animals.
View Article and Find Full Text PDFbioRxiv
January 2025
Department of Neurobiology and Biophysics, University of Washington School of Medicine, Seattle, WA 98195-7290, USA.
Acetylcholine modulates the network physiology of the hippocampus, a crucial brain structure that supports cognition and memory formation in mammals . In this and adjacent regions, synchronized neuronal activity within theta-band oscillations (4-10Hz) is correlated with attentive processing that leads to successful memory encoding . Acetylcholine facilitates the hippocampus entering a theta oscillatory regime and modulates the temporal organization of activity within theta oscillations .
View Article and Find Full Text PDFNature
January 2025
Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Glioblastoma (GBM) infiltrates the brain and can be synaptically innervated by neurons, which drives tumor progression. Synaptic inputs onto GBM cells identified so far are largely short-range and glutamatergic. The extent of GBM integration into the brain-wide neuronal circuitry remains unclear.
View Article and Find Full Text PDFGlia
January 2025
State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science and Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, P. R. China.
Astrocytes are the most abundant type of macroglia in the brain and play crucial roles in regulating neural development and functions. The diverse functions of astrocytes are largely determined by their morphology, which is regulated by genetic and environmental factors. However, whether and how the astrocyte morphology is affected by temperature remains largely unknown.
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