Biomedical subjects

Kevin L Briggman

Publications and source records attributed to Kevin L Briggman.

3 recordsLinked to original sources

PubMed2006

Imaging dedicated and multifunctional neural circuits generating distinct behaviors.

Central pattern generators (CPGs) control both swimming and crawling in the medicinal leech. To investigate whether the neurons comprising these two CPGs are dedicated or multifunctional, we used voltage-sensitive dye imaging to record from approximately 80% of the approximately 400 neurons in a segmental ganglion. By eliciting swimming and crawling in the same preparation, we were able to identify neurons that participated in either of the two rhythms, or both. More than twice as many cells oscillated in-phase with crawling (188) compared with swimming (90). Surprisingly, 84 of the cells (93%) that oscillated with swimming also oscillated with crawling. We then characterized two previously unidentified interneurons, cells 255 and 257, that had interesting activity patterns based on the imaging results. Cell 255 proved to be a multifunctional interneuron that oscillates with and can perturb both rhythms, whereas cell 257 is an interneuron dedicated to crawling. These results show that the swimming and crawling networks are driven by both multifunctional and dedicated circuitry.

Animals↗

PubMed2006

Towards neural circuit reconstruction with volume electron microscopy techniques.

Electron microscopy is the only currently available technique with a resolution adequate to identify and follow every axon and dendrite in dense neuropil. Reconstructions of large volumes of neural tissue, necessary to reconstruct even local neural circuits, have, however, been inhibited by the daunting task of serially sectioning and reconstructing thousands of sections. Recent technological developments have improved the quality of volume electron microscopy data and automated its acquisition. This opens up the prospect of reconstructing almost complete invertebrate and sizable fractions of vertebrate nervous systems. Such reconstructions of complete neural wiring diagrams could rekindle the tradition of relating neural function to the underlying neuroanatomical circuitry.

Animals↗

PubMed2006

From crawling to cognition: analyzing the dynamical interactions among populations of neurons.

By using multi-electrode arrays or optical imaging, investigators can now record from many individual neurons in various parts of nervous systems simultaneously while an animal performs sensory, motor or cognitive tasks. Given the large multidimensional datasets that are now routinely generated, it is often not obvious how to find meaningful results within the data. The analysis of neuronal-population recordings typically involves two steps: the extraction of relevant dynamics from neural data, and then use of the dynamics to classify and discriminate features of a stimulus or behavior. We focus on the application of techniques that emphasize interactions among the recorded neurons rather than using just the correlations between individual neurons and a perception or a behavior. An understanding of modern analysis techniques is crucially important for researchers interested in the co-varying activity among populations of neurons or even brain regions.

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