Rod and cone photoreceptor cells selectively contact different compartments of axon-bearing retinal horizontal cells in the mammalian retina. Cones synapse exclusively on the soma whereas rods synapse exclusively on a large axon terminal compartment. The possibility that rod signals can travel down the axon from terminal to soma has been proposed as a means of producing spectrally opponent interactions between rods and cones, but there is conflicting data about whether this actually occurs. The spectral overlap between rods and cones in mouse makes it difficult to stimulate rod and cone pigments separately. We therefore used optogenetic techniques to analyze photoreceptor inputs into horizontal somas by selectively expressing channelrhodopsin in rods and/or cones. Optogenetic stimulation of rods and cones both evoked large fast inward currents in horizontal cell somas. Cone-driven responses were abolished by eliminating synaptic release in a cone-specific knockout of the exocytotic calcium sensor, synaptot...

Since becoming president of SfN’s Greater Baltimore Chapter earlier this year, Kristina Nielsen has noted the chapter’s enthusiasm for sharing knowledge with the community. She has a lot of ideas — launching a website and establishing other communications channels among them — and is considering ways to further coordinate activities and recognize chapter members for their efforts. “I'm amazed by how much the students and postdocs are doing in terms of outreach. It's impressive,” she says. Here she shares her observations of the neuroscience community in Baltimore, outlines some of the numerous outreach activities the chapter coordinates among its constituent organizations, and explains how connecting with the Baltimore community improves science by opening conversations and encouraging youth to explore careers in the field.

Share your experiences and ideas about scientific cultural factors that can undermine rigorous research practices and identify solutions to these issues that can be employed by all members of the neuroscience community. The Foundations of Rigorous Neuroscience Research (FRN) program will engage members of the neuroscience community to raise awareness of barriers and solutions related to practicing rigorous research and create new resources that will empower neuroscientists at all career stages to implement these practices in their work.

As an undergraduate and first-time annual meeting attendee at Neuroscience 2018, my biggest goal was to learn new aspects of neuroscience, especially outside the bounds of my research project. I also wanted to develop my professional and presentation skills and to become more comfortable navigating a national conference. The meeting was more than I hoped for. I came away with knowledge that enlightened aspects of my research, and I had the opportunity to grow as both a scientist and a presenter. The best advice I could give undergrad attendees is to plan ahead, explore all of the sessions listed on SfN.org and in the Neuroscience Meeting Planner, and download the meeting app for your phone, which has helpful maps of the convention center. If you’re giving any sort of presentation, I cannot overstate the importance of practice. You can’t be too prepared. In this guide to the annual meeting for undergraduate students and other first-time attendees, I outline what to do to prepare, share how I chose sessions to attend, recount surprises and what I learned from them, and offer advice for how to have a successful SfN annual meeting.

Study Question We and others have recently identified molecularly distinct subpopulations of dopamine neurons within the ventral tegmental area (VTA). Our main question in the current study was: Is it possible to identify distinct behaviors that a specific VTA subpopulation contributes to? For example, what about the recently identified NeuroD6 subpopulation? Where do these neurons project, how do they signal, and what types of behaviors are they involved in? How This Research Advances What We Know Heterogeneity has become a central feature in many aspects of neuroscience, and this is true also for the VTA. This midbrain region was recognized in the 1960s to contain dopamine neurons, and VTA dopamine neurons have since then been shown to be involved in various aspects of reward-related behavior such as reward prediction, reinforcement, incentive salience, and motivation. Consequently, dysregulation of VTA neurons is correlated with severe brain disorders. While it is puzzling how such a small population of cells can be involved in so many different functions, clues have appeared in the form of cellular heterogeneity. VTA dopamine neurons, long believed to comprise a rather homogeneous population, can be sorted into subpopulations/subtypes based on features such as afferent and efferent projections, electrophysiological properties, and molecular identity, properties that likely ascribe distinct neurons different functional roles. The puzzle of how distinct VTA neurons contribute to behavior is important to solve, not least to help advance drug discovery of dopamine disorders. It has also become clear that the VTA contains GABA and glutamate-releasing neurons, as well as co-releasing neurons. These neurons affect dopamine neurons and play distinct functional roles, which means the VTA is heterogeneous is many ways.

TrainingSpace (TS) is an online hub that aims to make neuroscience educational materials more accessible to the global neuroscience community. As a hub, TS provides users with access to: - Multimedia educational content from courses, conference lectures, and laboratory exercises from some of the world’s leading neuroscience institutes and societies. - Study tracks to facilitate self-guided study. - Tutorials on tools and open science resources for neuroscience research. - A Q&A forum. - A neuroscience encyclopedia that provides users with access to over 1,000,000 publicly available datasets as well as links to literature references and scientific abstracts. Topics currently included in TS include: general neuroscience, clinical neuroscience, computational neuroscience, neuroinformatics, computer science, data science, and open science. All courses and conference lectures in TS include a general description, topics covered, links to prerequisite courses if applicable, and links to software described in or required for the course, as well as links to the next lecture in the course or more advanced related courses. To learn more about TrainingSpace, visit: https://training.incf.org/

As social animals, our mental health depends on interactions with others, but millions suffer from chronic isolation globally, of which solitary confinement is the extreme example. What are the effects of isolation on the brains and behavior of animals and people? What can animal studies reveal about the human brain, and how can findings influence how society and policymakers think of solitary confinement? What role do neuroscientists play in collecting data and sharing it with the public? This panel discussion comprising a neurobiologist, a psychologist, a physician, a lawyer, and an individual held in solitary confinement for 29 years attempts to illuminate some of these questions.

Material below is adapted from the SfN Short Course session How to Study the Origins of Sex Differences in Brain and Behavior, by Margaret M. McCarthy. Short Courses are daylong scientific trainings on emerging neuroscience topics and research techniques held the day before the start of SfN’s annual meeting. Scientists have known for nearly 60 years that the hormones produced by the endocrine system influence fetal brain development and subsequent adult behavior. Yet only now are researchers beginning to gain a greater understanding of how neuroscience and those hormones interact in both male and female animals. Sex is largely determined by an organism’s chromosomes. Mammals use an XY chromosome system in which biological females have two X chromosomes and biological males have both an X and Y, which carries the Sry gene that directs the development of the testes, the male gonads or sex glands. The testes arise early during fetal development and quickly start producing endocrine hormones that influence the growth and development of other sex organs and the masculinization or sexual differentiation of the brain.

Understanding the ability to self-evaluate decisions is an active area of research. This research has primarily focused on the neural correlates of self-evaluation during visual-tasks, and whether neural correlates before or after the primary decision contribute to self-reported confidence. This focus has been useful, yet the reliance on subjective confidence reports may confound our understanding of key every-day features of metacognitive self-evaluation: that decisions must be rapidly evaluated without explicit feedback, and unfold in a multisensory world. These considerations led us to hypothesise that an automatic domain-general metacognitive signal may be shared between sensory modalities, which we tested in the present study with multivariate decoding of electroencephalographic (EEG) data. Participants (N=21, 12 female) first performed a visual task with no request for self-evaluations of performance, prior to an auditory task that included rating decision confidence on each trial. A multivariate cla...

Material below summarizes the article Slow NMDA-Mediated Excitation Accelerates Offset-Response Latencies Generated via a Post-Inhibitory Rebound Mechanism, published on May 31, 2019, in eNeuro and authored by Ezhilarasan Rajaram, Carina Kaltenbach, Matthew J. Fischl, Leander Mrowka, Olga Alexandrova, Benedikt Grothe, Matthias H. Hennig, and Conny Kopp-Scheinpflug. Study Question A neuroscience textbook paints the neuron as receiving a good measure of excitatory and inhibitory inputs. Strong excitatory inputs depolarize the neuron to power an action potential, while inhibitory inputs hold the cell back by hyperpolarization. The neurons of the superior paraolivary nucleus (SPN) in the auditory brainstem of rodents embody the polar opposite. They receive predominantly inhibitory inputs. It has been shown that SPN neurons rely on strong inhibition to fire action potentials, by rebounding from hyperpolarization. This raises the question of what the role of excitation is in these neurons.