The McGill-Mouse-Miniscope platform: A standardized approach for high-throughput imaging of neuronal dynamics during behavior.

Understanding the rules that govern neuronal dynamics throughout the brain to subserve behavior and cognition remains one of the biggest challenges in neuroscience research. Recent technical advances enable the recording of increasingly larger neuronal populations to produce increasingly more sophisticated datasets. Despite bold and important open-science and data-sharing policies, these datasets tend to include unique data acquisition methods, behaviors, and file structures. Discrepancies between experimental protocols present key challenges in comparing data between laboratories and across different brain regions and species. Here, we discuss our recent efforts to create a standardized and high-throughput research platform to address these issues. The McGill-Mouse-Miniscope (M3) platform is an initiative to combine miniscope calcium imaging with standardized touchscreen-based animal behavioral testing. The goal is to curate an open-source and standardized framework for acquiring, analyzing, and accessing high-quality data of the neuronal dynamics that underly cognition throughout the brain in mice, marmosets, and models of disease. We end with a discussion of future developments and a call for users to adopt this standardized approach.

High frequency sensitivity to interaural onset time differences in the bat inferior colliculus.

Many neurons in the auditory midbrain are tuned to binaural cues. Two prominent binaural cues are the interaural level difference (ILD) and the interaural time difference (ITD). The ITD cue can further be subdivided into the ongoing envelope ITD cues and transient onset ITD cues. More is known about the sensitivity of single neurons to ongoing envelope ITDs compared to transient onset ITDs in the mammalian auditory system, particularly in bats. The current study examines the response properties of single neurons in the inferior colliculus (IC) of the big brown bat, Eptesicus fuscus, to onset ITDs in response to high frequency pure tones. Measures of neurons' dynamic ITD response revealed an average change of 36% of its maximum response within the behaviorally relevant range of ITDs (±50 µs). Across all IC neurons, we measured an average time-intensity trading ratio of 30 µs/dB in the sensitivity of the ITD response function to changing ILDs. Minimum and maximum ITD responses were clustered within a narrow range of ITDs. The average peak in the ITD response function was at 268 µs, a finding that is consistent with other non-echolocating mammals. Some ITD-sensitive neurons also showed weak facilitation of maximum response during binaural stimulation, compared to monaural stimulation. These results suggest that echolocating bats possess the potential to use onset ITD cues to assist in the azimuthal sound localization of ultrasonic frequencies.

Parental bonding and neuropsychological performance are associated with episodic simulation of future events in trauma-exposed patients with major depressive disorder.

INTRODUCTION: Major depressive disorder (MDD) and trauma-related disorders are associated with deficits in remembering the past and imagining the future (i.e., episodic simulation). We examined parental bonding and neuropsychological performance in relation to episodic simulation in trauma-exposed patients with recurrent MDD. METHODS: Trauma-exposed patients with MDD (n = 21) and matched controls (n = 20) completed a future-oriented Autobiographical Interview, the Parental Bonding Instrument, and a standardized neuropsychological battery. RESULTS: Patients with major depressive disorder generated fewer episodic details for future neutral events compared to controls. Although higher reported levels of maternal care were associated with increased specificity of negative future events among the patient group, higher maternal overprotection was related to decreased specificity of negative and positive future events. Higher levels of performance on measures of intelligence, verbal memory, executive functioning, and sustained attention were associated with increased specificity of future events. CONCLUSIONS: Maternal relations during childhood and neuropsychological performance are related to the specificity of episodic simulation in adult patients with MDD. Childhood experience continues to influence memory performance into adulthood.