Hiroshi Nishiyama

Associate Professor
Department of Neuroscience

The synaptic connections between neurons undergo continuous structural remodeling.

Phone: 512-232-8438

Office Location
NHB 3.151

Postal Address
The University of Texas at Austin
Department of Neuroscience, College of Natural Sciences
1 University Station C7000
Austin, TX 78712

Research Summary:

The synaptic connections between neurons undergo continuous structural remodeling even in the adult brain. However, we still have not largely understood the structural plasticity of neural circuitry in the context of brain function.

The long-term goal of my research is to illuminate the principles governing the structural plasticity of neural circuitry in the intact mammalian brain, under both normal (e.g. development, learning and memory) and pathologic conditions (e.g. neurodegeneration).

We have currently focused on the following questions:
How is axonal structural plasticity regulated in the adult brain during learning?
How does axonal remodeling proceed in real time following brain injury?
How is activity-dependent synaptic refinement achieved during development?

To address these questions, in vivo imaging of a genetically and physiologically tractable neuronal circuit is necessary. The cerebellar cortex is a particularly useful model system in this endeavor.

The cerebellum is composed of a relatively small number of cell types, arranged in a highly stereotypic fashion, and their interconnections have been extensively characterized. Therefore, our research utilizes the cerebellum as a primary model system and uses a combination of two-photon in vivo time-lapse imaging, virus-mediated gene delivery and neuronal tracing, and rodent behavioral trainings to address the questions above.

2015. Nishiyama, H. Dendritic translocation of climbing fibers: a new face of old phenomenon. Cerebellum 14, 1-3

2014. Learning-induced structural plasticity in the cerebellum. International Review of Neurobiology 117, 1-19 

2014 Nishiyama N, Colonna J, Shen E, Carrillo J, Nishiyama H., Long-term in vivo time-lapse imaging of synapse development and plasticity in the cerebellum., J Neurophys. 111 (1), 208-216

2013 Carrillo J, Cheng SY, Ko KW, Jones TA, Nishiyama H., The long-term structural plasticity of cerebellar parallel fiber axons and its modulation by motor learning., J Neurosci. 33: 8301-7

2013 Carrillo J, Nishiyama N, Nishiyama H., Dendritic translocation establishes the winner in cerebellar climbing fiber synapse elimination., J Neurosci. 33: 7641-53

2011 Kim HS, Seto-Ohshima A, Nishiyama H, Itohara S., Normal delay eyeblink conditioning in mice devoid of astrocytic S100B., Neurosci. Lett. 489: 148-53

2008 Tanaka M, Yamaguchi K, Tatsukawa T, Nishioka C, Nishiyama H, Theis M, Willecke K, Itohara S., Lack of Connexin43-mediated bergmann glial gap junctional coupling does not affect cerebellar long-term depression, motor coordination, or eyeblink conditioning., Front Behav Neurosci. 2: 1-14

2007 Nishiyama H, Fukaya M, Watanabe M, Linden DJ., Axonal motility and its modulation by activity are branch-type specific in the intact adult cerebellum., Neuron 56: 472-87

2007 Nishiyama H, Linden DJ., Pure spillover transmission between neurons., Nat. Neurosci. 10: 675-7

2004 Nishiyama H, Linden DJ., Differential maturation of climbing fiber innervation in cerebellar vermis., J Neurosci. 24: 3926-32