Bryan M. Hooks, PhD

  • Assistant Professor, Neurobiology




Education & Training

PhD, Harvard University (2007)

Campus Address

W1458 Starzl Biomedical Science Towerd

Research Grants

I am collaborating with Dr. Becky Seal (Pitt) and Dr. Eric Yttri (CMU) to study corticostriatal circuitry and its changes during dopamine depletion, such as in Parkinson’s Disease.

I am collaborating with Dr. Chip Gerfen (NIH) to trace cortical and striatal circuits throughout the brain using a combination of retrograde/anterograde viral reagents and whole brain imaging/reconstruction.

One-Line Research Description

Organization of mouse cortical circuitry underlying control of movement.

I am interested in understanding how the specific cell types in motor cortex are connected, and how these specific connections enable motor cortex to control movement. 

In the mammalian brain, different cortical areas are specialized for different functions. Motor cortex is specialized for the planning, initiation, control, and learning of movements. However, the precise computations performed in motor cortex circuits are not well understood. In particular, the specific circuit connections of defined cell types in motor cortex are not well described, how specific connections drive neuronal firing is not known, and which connections change strength during learning is also unknown. 

Progress has been limited since there were a variety of intermingled neuronal types in each cortical area and until recently it was not always possible to independently stimulate specific local and long-range pathways. Fortunately, the tools needed to define cortical circuits are being rapidly developed, including (a) means to reliably define and manipulate specific cell types and (b) methods to excite and quantify specific inputs. New transgenic lines, including some I am playing a role in characterizing, will label specific neuron populations in mouse neocortex, including specific subtypes of excitatory pyramidal neurons and inhibitory interneurons. This will enable targeted recording and excitation of specific cell types. Different cell types are believed to play distinct roles in the local circuit, so understanding their specific inputs will help explain the specific response properties of each cell type. New circuit mapping approaches using optical and genetic methods to render specific populations of presynaptic neurons excitable make it possible to quantify the connectivity of local and long-range inputs to different cortical cell types. Furthermore, I have begun to extend circuit mapping methods to comparing the strengths of multiple inputs onto the same neuron, independently stimulating two inputs using distinct colors of light. This will address whether individual neurons specialize to preferentially receive certain types of input. 

The results of both projects will leave me well positioned to take advantage of cell-type specific transgenic mice and modern circuit mapping methods to understand connectivity in motor cortex. In the short term, I intend to: (1) Understand how feedforward inhibition is recruited in motor cortex by distinct cortical and thalamic inputs. Specifically, we seek to know whether these inputs recruit the same subtypes of inhibitory interneurons (such as parvalbumin and somatostatin expressing interneurons), whether these inputs excite the same individual cells, and what rules govern the magnitude of feedforward excitation and inhibition from cortical and thalamic inputs to motor cortex. (2) Examine where in the cortical circuit the inputs from distinct motor thalamic nuclei are combined. This will help to address how subcortical regions involved in motor learning and action selection, relaying input via motor thalamus, act together to influence the output of motor cortex. (3) Understand how specific cell types of primary sensory areas excite specific pyramidal cell types in primary motor areas. 

Currently, the lab uses mouse motor and sensory cortex as model system. This allows us to take advantage of many cell-type specific mouse lines as well as optogentic tools developed for mice. Techniques we use include stereotaxic surgery, use of AAV for expressing a variety of optogenetic tools and fluorophores, mouse brain slice and laser-scanning microscope to map circuits, and anatomical techniques for reconstructing circuits. We will continue to develop new techniques to address questions of the neural basis for motor control. 

Representative Publications

Hooks BM, and Chen C (2020) Circuitry Underlying Experience-Dependent Plasticity in the Mouse Visual System. Neuron 106: 21-36.

Sugino K, Clark E, Schulmann A, Shima Y, Wang L, Hunt DL, Hooks BM, Trankner D, Chandrashekar J, Picard S, Lemire A, Spruston N, Hantman A, Nelson SB (2019) Mapping the transcriptional diversity of genetically and anatomically defined cell populations in the mouse brain. Elife. doi: 10.7554/eLife.38619. (Epub ahead of print)

Tappan SJ, Eastwood BS, O’Connor N, Wang Q, Ng L, Hooks BM, Gerfen CR, Hof PR, Schmitz C, Glaser JR (2019) Automatic navigation system for the mouse brain. J Comp Neurol. doi: 10.1002/cne.24635. (Epub ahead of print)

Eastwood BS, Hooks BM, Paletzki R, O’Connor NJ, Glaser JR, Gerfen CR (2019) Whole Mouse Brain Reconstruction and Registration to a Reference Atlas with Standard Histochemical Processing of Coronal Sections. J Comp Neurol. doi: 10.1002/cne.24602. (Epub ahead of print)

Gittis AH, Hooks BM, Gerfen CR (2019) “The Basal Ganglia” in Circuit Development (Section Editor Hongkui Zeng), Comprehensive Developmental Neuroscience Series, 2nd Edition (Series Editors John Rubenstein, Pasko Rakic, Bin Chen and Kenneth Kwan).

Kim T, Hooks BM, Cheetham CEJ (2019) “Circuit Development in Somatosensory Cortex” in Circuit Development (Section Editor Hongkui Zeng), Comprehensive Developmental Neuroscience Series, 2nd Edition (Series Editors John Rubenstein, Pasko Rakic, Bin Chen and Kenneth Kwan).

Papale AE and Hooks BM (2018) Circuit changes in motor cortex during motor skill learning. Neuroscience 368: 283-297.

Hooks BM, Papale AE, Paletzki R, Feroze MW, Eastwood BS, Couey JJ, Winnubst J, Chandrashekar J, Gerfen CR (2018) Topographic precision in sensory and motor corticostriatal projections varies across cell type and cortical area. Nat. Communications 9:3549. DOI: 10.1038/s41467-018-05780-7.

Hooks BM (2018) Dual channel photostimulation for independent excitation of two populations. Current Protocols in Neuroscience 11:e52 DOI: 10.1002/cpns.52.

Hooks BM (2017) Sensorimotor Convergence in Circuitry of the Motor Cortex. Neuroscientist 23: 251-263.

Viswanathan S, Williams ME, Bloss EB, Stasevich TJ, Speer CM, Nern A, Pfeiffer BD, Hooks BM, Li WP, English BP, Tian T, Henry GL, Macklin JJ, Patel R,Gerfen CR, Zhuang X, Wang Y, Rubin GM, Looger LL (2015) High-performance probes for light and electron microscopy. Nat Methods 12: 568-576.

Hooks BM, Lin JY, Guo C, and Svoboda K (2015) Dual channel circuit mapping reveals sensorimotor convergence in the primary motor cortex. J Neurosci 35: 4418-4426.

Suter BA, Yamawaki N, Borges K, Li X, Kiritani T, Hooks BM, Shepherd GMG (2014) Neurophotonics applications to motor cortex research: a review. Neurophotonics 1: 011008.

Louros SR, Hooks BM, Litvina L, Carvalho AL, Chen C (2014) A role for Stargazin in experience-dependent plasticity. Cell Reports 7:1614-1625.

Wang X, Hooks BM, Sun QQ (2014) Thorough GABAergic innervations of the entire axon initial segment revealed by an optogenetic laserspritzer. J Physiol 592: 4257-76.

Yang W, Carrasquillo Y, Hooks BM, Nerbonne JM, Burkhalter A (2013) Distinct balance of excitation and inhibition in an interareal feedforward and feedback circuit of mouse visual cortex. J Neurosci 33:17373-17384.

Hooks BM, Mao T, Gutnisky DA, Yamawaki N, Svoboda K, Shepherd GMG (2013) Organization of cortical and thalamic input to pyramidal neurons in mouse motor cortex. J Neurosci. 33:748-760.

Madisen L, Mao T, Koch H, Zhuo JM, Berenyi A, Fujisawa S, Hsu YW, Garcia AJ 3rd, Gu X, Zanella S, Kidney J, Gu H, Mao Y, Hooks BM, Boyden ES, Buzsáki G, Ramirez JM, Jones AR, Svoboda K, Han X, Turner EE, Zeng H (2012) A toolbox of Cre-dependent optogenetic transgenic mice for light-induced activation and silencing. Nat Neurosci. 15: 793-802.

Mao T, Kusefoglu D, Hooks BM, Huber D, Petreanu L, Svoboda K (2011) Long-range neuronal circuits underlying the interaction between sensory and motor cortex. Neuron 72:111-23.

Hooks BM, Hires SA, Zhang Y-X, Huber D, Petreanu L, Svoboda K, Shepherd GMG (2011) Laminar Analysis of Excitatory Local Circuits in Vibrissal Motor and Sensory Cortical Areas. PLoS Biol 9(1): e1000572. doi:10.1371/journal.pbio.1000572.

Svoboda, K., Hooks, B.M. and Shepherd, G.M.G.: Barrel Cortex. In: Handbook of Brain Microcircuits, pp. 31-38. (Grillner S and Shepherd GM, eds.) Oxford, 2010.

Komiyama T, Sato TR, O’Connor DH, Zhang YX, Huber D, Hooks BM, Gabitto M, and Svoboda K (2010) Learning-related fine-scale specificity imaged in motor cortex circuits of behaving mice. Nature 464: 1182-1186.*See recommendation inFaculty of 1000.

Suter BA, O’Connor T, Iyer V, Petreanu LT, Hooks BM, Kiritani T, Svoboda K, and Shepherd GMG (2010) Ephus: multipurpose data acquisition software for neuroscience experiments. Front. Neurosci 4: 1-12. doi:10.3389/fnins.2010.00053.

Hooks BM and Chen C (2008) Vision Triggers an Experience-Dependent Sensitive Period at the Retinogeniculate Synapse. J Neurosci 28: 4807-17.*See comment inCurr Opin Neurobio 19: 154-161.

Roy K, Murtie JC, El-Khodor BF, Edgar N, Sardi SP, Hooks BM, Benoit-Marand M, Chen C, Moore H, O'Donnell P, Brunner D, and Corfas G (2007) Loss of erbB signaling in oligodendrocytes alters myelin and dopaminergic function, a potential mechanism for neuropsychiatric disorders. PNAS 104: 8131-8136.

Hooks BM, and Chen C: A Model for Synaptic Refinement in Visual Thalamus. In: Development and Plasticity in Sensory Thalamus and Cortex, pp. 226-244. (Erzurumlu R, Guido W, and Molnar Z, eds.) Springer, 2006.

Hooks BM and Chen C (2006) Distinct Roles for Spontaneous and Visual Activity in Remodeling of the Retinogeniculate Synapse. Neuron 52: 281-291.*See comment inNeuron 52:221-2222 and Curr Opin Neurobio 19: 154-161.

Cai H, Stevens Kalceff MA, Hooks BM, and Lawn BR (1994) Cyclic Fatigue of a Mica-Containing Glass Ceramic at Hertzian Contacts. J Materials Research 9: 2654-2661.

Cai H, Padture NP, Hooks BM, Lawn BR (1994) Flaw Tolerance and Toughness-Curves in Two-Phase Particulate Composites: SiC/Glass System. J Europ Ceram Soc 13: 149-157.