Differential Subcellular Distribution and Release Dynamics of Cotransmitted Cholinergic and GABAergic Synaptic Inputs Modify Dopaminergic Neuronal Excitability.

We identified three types of monosynaptic cholinergic inputs spatially arranged onto medial substantia nigra dopaminergic neurons in male and female mice: cotransmitted acetylcholine (ACh)/GABA, GABA-only, and ACh only. There was a predominant GABA-only conductance along lateral dendrites and soma-centered ACh/GABA cotransmission. In response to repeated stimulation, the GABA conductance found on lateral dendrites decremented less than the proximally located GABA conductance, and was more effective at inhibiting action potentials. While soma-localized ACh/GABA cotransmission showed depression of the GABA component with repeated stimulation, ACh-mediated nicotinic responses were largely maintained. We investigated whether this differential change in inhibitory/excitatory inputs leads to altered neuronal excitability. We found that a depolarizing current or glutamate preceded by cotransmitted ACh/GABA was more effective in eliciting an action potential compared with current, glutamate, or ACh/GABA alone. This enhanced excitability was abolished with nicotinic receptor inhibitors, and modulated by T- and L-type calcium channels, thus establishing that activity of multiple classes of ion channels integrates to shape neuronal excitability.SIGNIFICANCE STATEMENT Our laboratory has previously discovered a population of substantia nigra dopaminegic neurons (DA) that receive cotransmitted ACh and GABA. This study used subcellular optogenetic stimulation of cholinergic presynaptic terminals to map the functional ACh and GABA synaptic inputs across the somatodendritic extent of substantia nigra DA neurons. We determined spatially clustered GABA-only inputs on the lateral dendrites while cotransmitted ACh and GABA clustered close to the soma. We have shown that the action of GABA and ACh in cotransmission spatially clustered near the soma play a critical role in enhancing glutamate-mediated neuronal excitability through the activation of T- and L-type voltage-gated calcium channels.

Detecting a hidden pandemic: The current state and future direction of screening and assessment tools for intimate partner violence-related brain injury.

Intimate partner violence (IPV) is a major global concern, and IPV victim-survivors are at an increased risk of brain injury (BI) due to the physical assaults. IPV-BI can encompass both mild traumatic brain injury (mTBI) and non-fatal strangulation (NFS), but IPV-BI often goes undetected and untreated due to a number of complicating factors. Therefore, the clinical care and support of IPV victim-survivors could be enhanced by BI screening and assessment in various settings (e.g., first responders, emergency departments, primary care providers, rehabilitation, shelters, and research). Further, appropriate screening and assessment for IPV-BI will support more accurate identifications, and prevalence estimates, improve understanding of health implications, and have the potential to inform policy decisions. Here we overview the seven available tools that have been used for IPV-BI screening and assessment purposes, including the BISA, BISQ-IPV, BAT-L/IPV, OSU TBI-ID, the HELPS, and the CHATS, and outline the advantages and disadvantages of these screening tools in the clinical, community, and research settings. Recommendations for further research to enhance the validity and utility of these tools are also included.

Asynchronous Delivery of a 400 Level, Partially Peer-Graded, Oral Presentation and Discussion Course in Systems Neuroscience for 60 Students during the COVID-19 Pandemic.

A 400-level undergraduate oral presentation and discussion course in Systems Neuroscience was delivered asynchronously online during the COVID-19 pandemic. Enrolled students banked their narrated oral presentations in video format online then engaged in peer evaluation in virtual classrooms through the course website. Student delivered their oral presentation and responded to peer questions at their leisure and convenience, without the stress and anxiety associated with a "live" performance delivery in front of their peers. A remote and asynchronously delivered course facilitated much more peer contact than "live" versions of the course, which included a total of 62 uploaded presentations, 301 video responses uploaded to 1985 questions posed by peers, a total of 1159 feedback questionnaires submitted, 1066 rankings submitted of viewed oral presentations, and 1091 scores submitted evaluating the quality of questions posed by reviewers of oral presentations. A major drawback in the remote, asynchronous deliver was the enormity of peer engagement through the course website portal, which was mostly blind to the instructor because of the inability to effectively cross-index data linked between the student entries in the LEARN course website and the uploaded videos stored within BONGO Video Assignment tool. Nonetheless, a consistent engagement of students, and the positive feedback from enrolled students, indicate that a future version of this oral/written discussion course will be delivered, in part, remotely and asynchronously, even without a mandated delivery of the course by a remote and asynchronous method due to the COVID-19 pandemic restrictions in 2020-2021.