Yosuke Morizawa

• PostDoc
• Associate Research Scientist at Columbia University

The canonical framework for testing pain and mechanical sensitivity in rodents is manual delivery of stimuli to the paw. However, this approach can produce variability in results, requires significant training, and is ergonomically unfavorable to the experimenter. To circumvent limitations in manual delivery of stimuli, we have created a device cal...

The canonical framework for testing pain and mechanical sensitivity in rodents is manual delivery of stimuli to the paw. However, this approach can produce variability in results, requires significant training, and is ergonomically unfavorable to the experimenter. To circumvent limitations in manual delivery of stimuli, we have created a device cal...

The canonical framework for testing pain and mechanical sensitivity in rodents is manual delivery of stimuli to the paw. However, this approach can produce variability in results, requires significant training, and is ergonomically unfavorable to the experimenter. To circumvent limitations in manual delivery of stimuli, we have created a device cal...

The enhancement of insulin secretion and of the proliferation of pancreatic β cells are promising therapeutic options for diabetes. Signals from the vagal nerve regulate both processes, yet the effectiveness of stimulating the nerve is unclear, owing to a lack of techniques for doing it so selectively and prolongedly. Here we report two optogenetic...

Actions from glial cells could affect the readiness and efficacy of learning and memory. Using a mouse cerebellar‐dependent horizontal optokinetic response motor learning paradigm, short‐term memory (STM) formation during the online training period and long‐term memory (LTM) formation during the offline rest period were studied. A large variability...

Astrocyte abnormalities have received great attention for their association with various diseases in the brain but not so much in the eye. Recent independent genome-wide association studies of glaucoma, optic neuropathy characterized by retinal ganglion cell (RGC) degeneration, and vision loss found that single-nucleotide polymorphisms near the ABC...

Synaptic pruning is a fundamental process of neuronal circuit refinement in learning and memory. Accumulating evidence suggests that glia participates in sculpting the neuronal circuits through synapse engulfment. However, whether glial involvement in synaptic pruning has a role in memory formation remains elusive. Using newly developed phagocytosi...

Unlike an electrical circuit, the hardware of the brain is susceptible to change. Repeated electrical brain stimulation mimics epileptogenesis. After such “kindling” process, a moderate stimulus would become sufficient in triggering a severe seizure. Here, we report that optogenetic neuronal stimulation can also convert the rat brain to a hyperexci...

The brain consists of neurons and much higher number of glial cells. They communicate each other, by which they control brain functions. The brain is highly vulnerable to several insults such as ischemia, but has a self-protective and self-repairing mechanisms against these. Ischemic tolerance or preconditioning is an endogenous neuroprotective phe...

Remodeling the brain by clearance of unnecessary network and debris is thought to be essential for the maintenance of brain function and microenvironment. Such events include phagocytosis, which is thought to be limited to the professional phagocytes, i.e., microglia in the brain. Here, we show that astrocytes, other type of glia, also show highly...

Astrocytes become reactive following various brain insults; however, the functions of reactive astrocytes are poorly understood. Here, we show that reactive astrocytes function as phagocytes after transient ischemic injury and appear in a limited spatiotemporal pattern. Following transient brain ischemia, phagocytic astrocytes are observed within t...

The original version of this Article contained an error in the spelling of the author Nobuhiko Ohno, which was incorrectly given as Noubuhiko Ohno. This has now been corrected in both the PDF and HTML versions of the Article.

The bladder urothelium is more than just a barrier. When the bladder is distended, the urothelium functions as a sensor to initiate the voiding reflex, during which it releases ATP via multiple mechanisms. However, the mechanisms underlying this ATP release in response to the various stretch stimuli caused by bladder filling remain largely unknown....

Microglia survey the brain environment by sensing several types of diffusible molecules, among which extracellular nucleotides released/leaked from damaged cells have central roles. Microglia sense ATP or other nucleotides by multiple P2 receptors, after which they change into several different phenotypes. However, so far, it is largely unknown whe...

Methylmercury (MeHg) is a well known environmental pollutant that induces serious neuronal damage. Although MeHg readily crosses the blood-brain barrier, and should affect both neurons and glial cells, how it affects glia or neuron-to-glia interactions has received only limited attention. Here, we report that MeHg triggers ATP/P2Y receptor signals...

Since gonadal female hormones act on and protect neurons, it is well known that the female brain is less vulnerable to stroke or other brain insults than the male brain. Although glial functions have been shown to affect the vulnerability of the brain, little is known if such a sex difference exists in glia, much less the mechanism that might cause...