Paradoxical effects of external modulation of inhibitory interneurons.

@article{Tsodyks1997, abstract = {The neocortex, hippocampus, and several other brain regions contain populations of excitatory principal cells with recurrent connections and strong interactions with local inhibitory interneurons. To improve our understanding of the interactions among these cell types, we modeled the dynamic behavior of this type of network, including external inputs. A surprising finding was that increasing the direct external inhibitory input to the inhibitory interneurons, without directly affecting any other part of the network, can, in some circumstances, cause the interneurons to increase their firing rates. The main prerequisite for this paradoxical response to external input is that the recurrent connections among the excitatory cells are strong enough to make the excitatory network unstable when feedback inhibition is removed. Because this requirement is met in the neocortex and several regions of the hippocampus, these observations have important implications for understanding the responses of interneurons to a variety of pharmacological and electrical manipulations. The analysis can be extended to a scenario with periodically varying external input, where it predicts a systematic relationship between the phase shift and depth of modulation for each interneuron. This prediction was tested by recording from interneurons in the CA1 region of the rat hippocampus in vivo, and the results broadly confirmed the model. These findings have further implications for the function of inhibitory and neuromodulatory circuits, which can be tested experimentally.}, address = {Department of Neurobiology, Weizmann Institute, Rehovot 76100, Israel.}, author = {Tsodyks, M. V. and Skaggs, W. E. and Sejnowski, T. J. and McNaughton, B. L. }, citeulike-article-id = {3037035}, issn = {0270-6474}, journal = {The Journal of neuroscience : the official journal of the Society for Neuroscience}, keywords = {inhibition}, month = {June}, number = {11}, pages = {4382--4388}, posted-at = {2008-07-23 15:52:25}, priority = {2}, title = {Paradoxical effects of external modulation of inhibitory interneurons.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/9151754}, volume = {17}, year = {1997} }

TY - JOUR ID - Tsodyks1997 L3 - citeulike-article-id:3037035 N2 - The neocortex, hippocampus, and several other brain regions contain populations of excitatory principal cells with recurrent connections and strong interactions with local inhibitory interneurons. To improve our understanding of the interactions among these cell types, we modeled the dynamic behavior of this type of network, including external inputs. A surprising finding was that increasing the direct external inhibitory input to the inhibitory interneurons, without directly affecting any other part of the network, can, in some circumstances, cause the interneurons to increase their firing rates. The main prerequisite for this paradoxical response to external input is that the recurrent connections among the excitatory cells are strong enough to make the excitatory network unstable when feedback inhibition is removed. Because this requirement is met in the neocortex and several regions of the hippocampus, these observations have important implications for understanding the responses of interneurons to a variety of pharmacological and electrical manipulations. The analysis can be extended to a scenario with periodically varying external input, where it predicts a systematic relationship between the phase shift and depth of modulation for each interneuron. This prediction was tested by recording from interneurons in the CA1 region of the rat hippocampus in vivo, and the results broadly confirmed the model. These findings have further implications for the function of inhibitory and neuromodulatory circuits, which can be tested experimentally. IS - 11 JF - The Journal of neuroscience : the official journal of the Society for Neuroscience SN - 0270-6474 AD - Department of Neurobiology, Weizmann Institute, Rehovot 76100, Israel. EP - 4388 TI - Paradoxical effects of external modulation of inhibitory interneurons. VL - 17 SP - 4382 KW - inhibition AU - Tsodyks, MV AU - Skaggs, WE AU - Sejnowski, TJ AU - McNaughton, BL PY - 1997/06/01/ UR - http://view.ncbi.nlm.nih.gov/pubmed/9151754 ER -