Matthew I. Banks
- Associate Professor, Department of Anesthesiology
- (608) 261-1143
Ph.D. University of Wisconsin- Madison
GABAA Receptors and the Dynamics of Cortical Inhibitory Circuits
Research Description:Sensory and cognitive information is represented in the neocortex in the spatiotemporal firing patterns of cells within neural networks. Research in my lab focuses on how these firing patterns arise (circuitry and stimulus coding), how they are altered upon changes in awareness (e.g. upon loss of consciousness (LOC) induced by general anesthetics), and the causal relationship between these changes in stimulus representation and changes in awareness. Current theories of the neural basis of sensory awareness suggest that neocortex is constantly comparing expected with observed sensory information. This comparison arises through the integration of ascending inputs from the sensory periphery via 'core' thalamo-cortical (TC) inputs with descending/modulatory cortico-cortical (CC) and 'matrix' TC inputs within the same or other sensory modalities. There is indirect evidence indicating that this integrative process is disrupted in slow wave sleep and upon anesthesia LOC. Although integration of ascending and descending/modulatory inputs to the column is widely believed to be a critical component of sensory awareness and likely a target for general anesthetics, there are several fundamental unanswered questions that motivate our research program.
(1) How does this integration process occur, and what is the net effect on activity in the column? For example, do descending/modulatory inputs have a net excitatory or inhibitory effect? Are specific cell subpopulations targeted? Is the integration primarily at the single cell or network level? At what level(s) in the cortical hierarchy is this integrative process critical, and how does this change with stimulus and task demands?
(2) What do general anesthetics do to this integrative process and what is the mechanism of their effect? Is there a causal relationship between these effects and LOC? Are effects at some level(s) in the cortical hierarchy more important for producing LOC? Do all agents that cause LOC share a common effect on columnar processing?To answer these questions, we use auditory cortex in mice and rats as a model system, and we apply optogenetic, imaging and electrophysiological techniques in an acute slice preparation, and electrophysiological and behavioral techniques in vivo. In vivo, we record from the entire cortical column or from multiple loci in the same layer using multielectrode arrays, and we selectively activate core TC versus matrix TC/descending CC inputs using simple auditory versus visual stimuli (which trigger multimodal responses in auditory regions), respectively. In brain slices, we can ask detailed questions about synaptic physiology, cellular properties and network activity, and we can selectively activate core TC versus matrix TC and CC input pathways. As for experiments in vivo, we can record from the entire column at once using multichannel electrodes or calcium imaging, and we can use optognetic techniques to activate specific afferent pathways and to control activity in selected subpopulations of cortical cells.
- Raz A, Grady SM, Krause BM, Uhlrich DJ, Manning KA and Banks MI (2014) Preferential effect of isoflurane on top-down vs. bottom-up pathways in sensory cortex. Front. Syst. Neurosci. 8:191. doi: 10.3389/fnsys.2014.00191
- Krause BM, Raz A, Uhlrich DJ, Smith PH, Banks MI (2014) Spiking in auditory cortex following thalamic stimulation is dominated by cortical network activity. Front Syst Neurosci. 8:170. doi: 10.3389/fnsys.2014.00170. PMID: 25285071
- Nir Y, Vyazovskiy VV, Cirelli C, Banks MI, Tononi G. (2013) Auditory Responses and Stimulus-Specific Adaptation in Rat Auditory Cortex are Preserved Across NREM and REM Sleep. Cereb Cortex. 2013 Dec 8. PMID: 24323498
- Krause BM and Banks MI (2013) Analysis of stimulus-related activity in rat auditory cortex using complex spectral coefficients. J Neurophysiol, published ahead of print May 8, 2013, doi:10.1152/jn.00187.2013, PMID: 23657279.
- Smith PH, Manning KA, Uhlrich DJ, Banks MI (2012) Evaluation of inputs to rat auditory cortex from the ventral and dorsal divisions of the medial geniculate nucleus. J Comp Neurol. 520(1):34-51. PMC3320111
- Banks MI, Uhlrich DJ, Smith PH, Krause BM, Manning KA (2011) Descending projections from extrastriate visual cortex modulate responses of cells in primary auditory cortex. Cerebral Cortex, 21: 2620-38. PMC3183425.
- Hentschke H, Benkwitz C, Banks MI, Perkins MG, Homanics GE, Pearce RA (2009) Altered GABAA,slow inhibition and network oscillations in mice lacking the GABAA receptor beta3 subunit. J Neurophysiol. 102(6):3643-55. PMC2804419
- Ling, C., Verbny YI, Banks MI, Sandor M, Fabry Z (2008) In situ activation of antigen-specific CD8+ T cells in the presence of antigen in organotypic brain slices. J. Immunol, 180:8393-8399.
- Hentschke H, Perkins MG, Pearce RA, Banks MI (2007) Muscarinic blockade weakens interaction of gamma with theta rhythms in mouse hippocampus. Eur J Neuroscience, 26:1642–1656.
- Burlingame RH, Shrestha S, Rummel MR, Banks MI (2007) Sub-hypnotic doses of isoflurane impair auditory discrimination in rats. Anesthesiology, 106:754-762.
- Verbny YI, Erdélyi F, Szabó G, Banks MI (2006) Properties of a population of GABAergic cells in murine auditory cortex weakly excited by thalamic stimulation. J Neurophysiology, 96:3194-3208.
- Merriam EB, Netoff TI, Banks MI (2005) Bistable network behavior of layer I interneurons in auditory cortex. J Neuroscience, 25:6175-6186.
- Verbny YI, Merriam EB, Banks MI (2005) Modulation of g-aminobutyric acid type A receptor-mediated spontaneous inhibitory postsynaptic currents in auditory cortex by midazolam and isoflurane. Anesthesiology,102:962-969.
- Perouansky M, Banks MI, Pearce RA (2005) Differential effects of the non-immobilizer 1,2dichlorohexafluorocyclobutane (F6, 2N) and isoflurane on extrasynaptic GABAA receptors. Anesthesia and Analgesia, 100(6):1667-73.
- Netoff TI, Banks MI, Dorval AD, Acker CD, Haas JS, Kopell N, White JA (2005) Synchronization in Hybrid Neuronal Networks of the Hippocampal Formation. J Neurophysiol, 93(3):1197-208.