Biology subjects

Hassani, S.-A.

Publications and source records attributed to Hassani, S.-A..

3 recordsLinked to original sources

bioRxiv2026

Cognitive engagement induces area-specific fingerprints of dopamine, acetylcholine, serotonin, glutamate and GABA in prefrontal cortex and striatum

Cholinergic, dopaminergic and serotonergic neuromodulation has pervasive effects on circuit functions in prefrontal cortex (PFC) and striatum and interact with glutamatergic and GABAergic transmission. But how these neurochemicals interact during cognitive engagement is largely unknown and inferred from studying few neuromodulators at a time. Here, we sampled the extracellular availabilities of five neurochemicals in the PFC and striatum of nonhuman primates and tested how they changed when subjects switched from rest to engage in a cognitive set shifting task using miniaturized probes for diffusion-based solid-phase microextraction. Cognitive engagement was best predicted by GABAergic and cholinergic changes in the PFC, and dopaminergic and cholinergic changes in the striatum. Glutamate co-modulated with acetylcholine across states in both the PFC and striatum, while serotonin changes in PFC and striatum correlated consistent with common external modulation. These findings document an area-specific multi-neuromodulatory fingerprint of an adaptive cognitive state in the fronto-striatal network of the nonhuman primate brain. TeaserEngaging in a cognitive task reshapes neurochemical profiles across the fronto-striatal network of the primate brain

neuroscience↗

bioRxiv2019

Cell-type Specific Learning of Attentional Gating in Primate Striatum

Cognitive flexibility depends on a fast neural learning mechanism for enhancing momentary relevant over irrelevant information. A possible neural mechanism realizing this enhancement uses fast-spiking interneurons (FSIs) in the striatum to train striatal projection neurons to gate relevant and suppress distracting cortical inputs. We found support for such a mechanism in nonhuman primates during the flexible adjustment of visual attention. FSIs gated visual attention cues during feature-based learning. One FSI population showed stronger inhibition during learning, while another FSI subpopulation showed weaker inhibition after learning signifying post-learning disinhibition. Additionally, a smaller neural subpopulation increased activity when salient distractor events were successfully suppressed. These findings highlight that fast behavioral learning of feature relevance is accompanied by fast neural learning of cell-type specific cortico-striatal gating.

neuroscience↗

bioRxiv2019

Multi-Neuromodulator Measurements across Fronto-Striatal Network Areas of the Behaving Macaque using Solid-Phase Microextraction

Different neuromodulators rarely act independent from each other to modify neural processes but are instead co-released, gated, or modulated. To understand this interdependence of neuromodulators and their collective influence on local circuits during different brain states, it is necessary to reliably extract local concentrations of multiple neuromodulators in vivo. Here we describe results using solid phase microextraction (SPME), a method providing sensitive, multi-neuromodulator measurements. SPME is a sampling method that is coupled with mass spectrometry to quantify collected analytes. Reliable measurements of glutamate, dopamine, acetylcholine and choline were made simultaneously within frontal cortex and striatum of two macaque monkeys (Macaca mulatta) during goal-directed behavior. We find glutamate concentrations several orders of magnitude higher than acetylcholine and dopamine in all brain regions. Dopamine was reliably detected in the striatum at tenfold higher concentrations than acetylcholine. Acetylcholine and choline concentrations were detected with high consistency across brain areas, within monkeys and between monkeys. These findings illustrate that SPME microprobes provide a versatile novel tool to characterize multiple neuromodulators across different brain areas in vivo to understand the interdependence and co-variation of neuromodulators during goal directed behavior. Such data will be important to better distinguish between different behavioral states and characterize dysfunctional brain states that may be evident in psychiatric disorders.

neuroscience↗