Browsing by keyword "basolateral amygdala"

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    • Binge Alcohol Drinking Alters Synaptic Processing of Executive and Emotional Information in Core Nucleus Accumbens Medium Spiny Neurons
      Kolpakova, Jenya; van der Vinne, Vincent; Gimenez-Gomez, Pablo; Le, Timmy; You, In-Jee; Zhao-Shea, Rubing; Velazquez-Marrero, Cristina; Tapper, Andrew R.; Martin, Gilles E. (2021-11-16)
      The nucleus accumbens (NAc) is a forebrain region mediating the positive-reinforcing properties of drugs of abuse, including alcohol. It receives glutamatergic projections from multiple forebrain and limbic regions such as the prefrontal cortex (PFCx) and basolateral amygdala (BLA), respectively. However, it is unknown how NAc medium spiny neurons (MSNs) integrate PFCx and BLA inputs, and how this integration is affected by alcohol exposure. Because progress has been hampered by the inability to independently stimulate different pathways, we implemented a dual wavelength optogenetic approach to selectively and independently stimulate PFCx and BLA NAc inputs within the same brain slice. This approach functionally demonstrates that PFCx and BLA inputs synapse onto the same MSNs where they reciprocally inhibit each other pre-synaptically in a strict time-dependent manner. In alcohol-naive mice, this temporal gating of BLA-inputs by PFCx afferents is stronger than the reverse, revealing that MSNs prioritize high-order executive processes information from the PFCx. Importantly, binge alcohol drinking alters this reciprocal inhibition by unilaterally strengthening BLA inhibition of PFCx inputs. In line with this observation, we demonstrate that in vivo optogenetic stimulation of the BLA, but not PFCx, blocks binge alcohol drinking escalation in mice. Overall, our results identify NAc MSNs as a key integrator of executive and emotional information and show that this integration is dysregulated during binge alcohol drinking.

    • Binge Alcohol Drinking Alters the Differential Control of Cholinergic Interneurons over Nucleus Accumbens Medium Spiny Neurons
      Kolpakova, Jenya (2022-05-06)
      Striatal cholinergic interneurons (ChIs) play a central role in basal ganglia function by regulating associative learning and reward processing. Drug addiction, such as alcoholism, is often described to hijack the natural reward system. In the nucleus accumbens (NAc), a brain region that mediates rewarding properties of substance of abuse, ChIs regulate glutamatergic, dopaminergic, and GABAergic neurotransmission. However, it is unclear how ChIs orchestrate the control of these neurotransmitters to determine the excitability of medium spiny neurons (MSNs), the NAc output neurons that translate accumbens electrical activity into behavior. Combining ex vivo electrophysiology, fast scan cyclic voltammetry and optogenetics approaches, I have demonstrated that stimulating NAc ChIs decreases the spontaneous excitatory postsynaptic currents (sEPSCs) frequency of both D1- and D2-MSNs through different mechanisms. While this effect in D1-MSNs was mediated by dopamine, it resulted from a direct control of glutamate release by ChIs in D2-MSNs. Interestingly, after two weeks of binge alcohol drinking, the effect of ChI stimulation on glutamate release was reversed in D1-MSNs, while its effect on D2-MSNs remained unchanged. Finally, in vivo optogenetic stimulation of NAc ChIs significantly increased alcohol consumption compared to unstimulated mice, but failed to alter mouse locomotor activity and saccharine or water consumption. Together, these results identify ChIs as a key modulator of NAc circuit activity and as a potential therapeutic target for alcohol use disorder.

    • Investigating Methodological Differences in the Assessment of Dendritic Morphology of Basolateral Amygdala Principal Neurons-A Comparison of Golgi-Cox and Neurobiotin Electroporation Techniques
      Klenowski, Paul M.; Wright, Sophie E.; Mu, Erica W. H.; Noakes, Peter G.; Lavidis, Nickolas A.; Bartlett, Selena E.; Bellingham, Mark C.; Fogarty, Matthew J. (2017-12-19)
      Quantitative assessments of neuronal subtypes in numerous brain regions show large variations in dendritic arbor size. A critical experimental factor is the method used to visualize neurons. We chose to investigate quantitative differences in basolateral amygdala (BLA) principal neuron morphology using two of the most common visualization methods: Golgi-Cox staining and neurobiotin (NB) filling. We show in 8-week-old Wistar rats that NB-filling reveals significantly larger dendritic arbors and different spine densities, compared to Golgi-Cox-stained BLA neurons. Our results demonstrate important differences and provide methodological insights into quantitative disparities of BLA principal neuron morphology reported in the literature.