Demonstrating Cerebral Vascular Networks: A Comparison of Methods for the Teaching Laboratory

One challenge of neuroscience educators is to make accessible to students as many aspects of brain structure and function as possible. The anatomy and function of the cerebrovasculature is among many topics of neuroscience that are underrepresented in undergraduate neuroscience education. Recognizing this deficit, we evaluated methods to produce archival tissue specimens of the cerebrovasculature and the “neurovascular unit” for instruction and demonstration in the teaching lab. An additional goal of this project was to identify the costs of each method as well as to determine which method(s) could be adapted into lab exercises, where students participate in the tissue preparation, staining, etc. In the present report, we detail several methods for demonstrating the cerebrovasculature and suggest that including this material can be a valuable addition to more traditional anatomy/physiology demonstrations and exercises

Utility and Versatility of Extracellular Recordings from the Cockroach for Neurophysiological Instruction and Demonstration

The principles of neurophysiology continue to be challenging topics to teach in the context of undergraduate neuroscience education. Laboratory classes containing neurophysiological demonstrations and exercises are, therefore, an important and necessary complement for covering those subjects taught in lecture-based courses. We developed a number of simple yet very instructive exercises, described below, which make use of extracellular recordings from different sensory systems of the cockroach (Periplanta americana). The compendium we developed provides students with hands-on demonstrations of several commonly taught topics of neurophysiology including sensory coding by neural activity

Teaching with Big Data: Report from the 2016 Society for Neuroscience Teaching Workshop

As part of a series of workshops on teaching neuroscience at the Society for Neuroscience annual meetings, William Grisham and Richard Olivo organized the 2016 workshop on Teaching Neuroscience with Big Data. This article presents a summary of that workshop. Speakers provided overviews of open datasets that could be used in teaching undergraduate courses. These included resources that already appear in educational settings, including the Allen Brain Atlas (presented by Joshua Brumberg and Terri Gilbert), and the Mouse Brain Library and GeneNetwork (presented by Robert Williams). Other resources, such as NeuroData (presented by William R. Gray Roncal), and OpenFMRI, NeuroVault, and Neurosynth (presented by Russell Poldrack) have not been broadly utilized by the neuroscience education community but offer obvious potential. Finally, William Grisham discussed the iNeuro Project, an NSF-sponsored effort to develop the necessary curriculum for preparing students to handle Big Data. Linda Lanyon further elaborated on the current state and challenges in educating students to deal with Big Data and described some training resources provided by the International Neuroinformatics Coordinating Facility. Neuroinformatics is a subfield of neuroscience that deals with data utilizing analytical tools and computational models. The feasibility of offering neuroinformatics programs at primarily undergraduate institutions was also discussed

Novel in silico Method for Teaching Cytoarchitecture, Cellular Diversity, and Gene Expression in the Mammalian Brain

Neuroanatomy can be a challenging topic for undergraduates, making the development of new methods of instruction an important goal of neuroscience educators. In the present report we describe the utility and versatility of the Allen Brain Atlas as a novel tool for instruction of several important anatomical principles of the mammalian central nervous system. Using this digital database, we detail how instructors of laboratory or lecture-based courses can demonstrate cytoarchitecture, cellular diversity, and gene expression profiles of the brain

The Impact of Perineuronal Net Digestion using Chondroitinase ABC on the Intrinsic Physiology of Cortical Neurons

Perineuronal nets (PNNs) are a form of aggregate Extracellular Matrix (ECM) in the brain. Recent evidence suggests that the postnatal deposition of PNNs may play an active role in regulating neuroplasticity and, potentially, neurological disorders. Observations of high levels of PNNs expression around somas, proximal dendrites, and axon initial segments of a subtype of neurons have also led to proposals that PNNs may modulate the intrinsic properties of the neurons they ensheathe. While high levels of PNNs are postnatally expressed throughout the neocortex, it is still unclear how they impact the neuronal physiology of the many classes and subtypes of neurons that exist. In this study, we demonstrate that Chondroitinase ABC digestion of PNNs from acute cortical slices from juvenile mice (P28-35) resulted in neuron specific impacts on intrinsic physiology. Fast spiking interneurons showed decreased input resistance, resting membrane potential, reduced action potential peaks and altered spontaneous synaptic inputs. Low Threshold Spiking interneurons showed altered rebound depolarization’s and decreased frequency of spontaneous synaptic inputs. Putative excitatory neurons; regular spiking, bursting, and doublet phenotypes did not demonstrate any alterations. Our data indicate that chABC sensitive PNNs may subtype specifically regulate the intrinsic and synaptic physiology of inhibitory interneurons

Barrels XXXII Meeting Report: Whiskers in the Windy City

The 32nd Annual Barrels meeting was hosted at the Northwestern University Feinberg School of Medicine in Chicago, Illinois on October 17th and 18th, 2019. The annual meeting brings together researchers who utilize the rodent whisker-to-barrel system as a means to understand cortical function and development. This year’s meeting focused on social behaviors, development and cerebellar functions within the barrel system and beyond

Undergraduate Neuroscience Education in the U.S.: An Analysis using Data from the National Center for Education Statistics

Despite an apparent increase in undergraduate neuroscience programs offered by colleges and universities, there has been little effort to document this growth. In the present report we describe our analysis of the expansion of undergraduate neuroscience programs of study over more than 20 years and detail a number of institutional characteristics of colleges and universities that offer undergraduate neuroscience programs. These data reveal more than 100 institutions with undergraduate neuroscience programs as well as over 2000 college graduates that majored in neuroscience in 2008–2009. Understanding the current number as well as growth trends of undergraduate neuroscience programs found in U.S. colleges and universities has implications for neuroscience educators as well as for the funding of neuroscience research and educational activities

Sensory Deprivation Alters Aggrecan and Perineuronal Net Expression in the Mouse Barrel Cortex

An important role for the neural extracellular matrix in modulating cortical activity-dependent synaptic plasticity has been established by a number of recent studies. However, identification of the critical molecular components of the neural matrix that mediate these processes is far from complete. Of particular interest is the perineuronal net (PN), an extracellular matrix component found surrounding the cell body and proximal neurites of a subset of neurons. Because of the apposition of thePNto synapses and expression of this structure coincident with the close of the critical period, it has been hypothesized that nets could play uniquely important roles in synapse stabilization and maturation. Interestingly, previous work has also shown that expression of PNs is dependent on appropriate sensory stimulation in the visual system. Here, we investigated whether PNs in the mouse barrel cortex are expressed in an activity-dependent manner by manipulating sensory input through whisker trimming. Importantly, this manipulation did not lead to a global loss of PNs but instead led to a specific decrease in PNs, detected with the antibody Cat-315, in layer IV of the barrel cortex. In addition, we identified a key activity-regulated component of PNs is the proteoglycan aggrecan. We also demonstrate that these Cat-315-positive neurons virtually all also express parvalbumin. Together, these data are in support of an important role for aggrecan in the activity-dependent formation of PNs on parvalbumin-expressing cells and suggest a role for expression of these nets in regulating the close of the critical period

Development and Sensory Experience Dependent Regulation of Microglia in Barrel Cortex

The barrel cortex is within the primary somatosensory cortex of the rodent, and processes signals from the vibrissae. Much focus has been devoted to the function of neurons, more recently, the role of glial cells in the processing of sensory input has gained increasing interest. Microglia are the principal immune cells of the nervous system that survey and regulate the cellular constituents of the dynamic nervous system. We investigated the normal and disrupted development of microglia in barrel cortex by chronically depriving sensory signals via whisker trimming for the animals’ first postnatal month. Using immunohistochemistry to label microglia, we performed morphological reconstructions as well as densitometry analyses as a function of developmental age and sensory experience. Findings suggest that both developmental age and sensory experience has profound impact on microglia morphology. Following chronic sensory deprivation, microglia undergo a morphological transition from a monitoring or resting state to an altered morphological state, by exhibiting expanded cell body size and retracted processes. Sensory restoration via whisker regrowth returns these morphological alterations back to agematched control values. Our results indicate that microglia may be recruited to participate in the modulation of neuronal structural remodeling during developmental critical periods and in response to alteration in sensory input