BRIEF COMMUNICATION Region-specific changes in the immunoreactivity of TRPV4 expression in the central nervous system of SOD1 G93A transgenic mice as an in vivo model of amyotrophic lateral sclerosis Jae Chul Lee • Kyeung Min Joo • Soo Young Choe • Choong Ik Cha Received: 26 March 2012 / Accepted: 6 June 2012 / Published online: 20 June 2012 Ó Springer Science+Business Media B.V. 2012 Abstract Transient receptor potential vanilloid 4 (TRPV4) is a broadly expressed Ca 2? -permeable cation channel in the vanilloid subfamily of transient receptor potential channels. It is activated by warm temperature, lipids downstream of arachidonic acid metabolism, hypoosmo- larity, or mechanical stimulation. In the present study, we used SOD1 G93A mutant transgenic mice as the animal model of amyotrophic lateral sclerosis (ALS) and investi- gated the changes of TRPV4 immunoreactivity in the central nervous system of these mice by immunohisto- chemical studies. An increased expression of TRPV4 was pronounced in the cerebral cortex, hippocampal formation, thalamus, cerebellum and spinal cord of symptomatic SOD1 G93A transgenic mice. In the cerebral cortex, TRPV4 immunoreactivity was significantly increased in pyramidal cells of SOD1 G93A transgenic mice. In the hippocampal formation, pyramidal cells of the CA1-3 areas and in the granule cells of the dentate gyrus demonstrated increased TRPV4 immunoreactivity. In addition, TRPV4 immuno- reactivity was increased in the spinal cord, thalamus and cerebellum of the symptomatic SOD1 G93A transgenic mice. This study, which showed increased TRPV4 in different brain and spinal cord regions of SOD1 G93A transgenic mice, may provide clues to the understanding of many basic neuronal functions in ALS. These findings suggest a role for TRPV4 in the neuronal functions in ALS but the mechanisms and functional implications of increased TRPV4 require elucidation. Keywords Amyotrophic lateral sclerosis (ALS) Á SOD1 G93A transgenic mice Á TRPV4 Á Cerebral cortex Á Hippocampus Á Thalamus Introduction Amyotrophic lateral sclerosis (ALS), commonly known as Lou Gehrig’s disease, is a progressive and fatal adult-onset neurodegenerative disease that is characterized by a selective loss of central and peripheral motor neurons in the brain and spinal cord (Cleveland and Rothstein 2001). Although the etiological and pathological factors that cause motor neuron degeneration in ALS have not been identi- fied, accumulating evidence has confirmed that the etiolo- gies of sporadic (SALS) and familial ALS (FALS) share common mechanisms and that the study of FALS cases can lead to a better grasp of SALS (Rowland and Shneider 2001). FALS accounts for fewer than 10 % of all diag- nosed cases, of which a quarter are associated with domi- nantly inherited mutations in the Cu/Zn superoxide dismutase (SOD1) gene (Cleveland and Rothstein 2001; Rowland and Shneider 2001). A growing body of evidence implicates excitotoxic processes in motor neuron degeneration Co-correspondence: S. Y. Choe and C. I. Cha. J. C. Lee Á K. M. Joo Á C. I. Cha (&) Department of Anatomy, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul 110-799, Korea e-mail: cicha@snu.ac.kr J. C. Lee Á S. Y. Choe Department of Biology, School of Life Sciences, Chungbuk National University, Cheongju 361-763, Republic of Korea e-mail: schoe@chungbuk.ac.kr 123 J Mol Hist (2012) 43:625–631 DOI 10.1007/s10735-012-9432-0