COM4S_M.TTF

Research Focus

Astrocytes are star-like cells and populous in the brain. They have long been functionally considered as structural, metabolic and functional supportive cells in the central nervous system (CNS). Accumulating recent research results also suggests that this glial type modulate neuronal signal transmission and may also be involved in the brain signaling processing through different mechanisms. However, it remains to be determined whether these and other unknown functions are carried out by functionally homogenous or heterogeneous astrocyte population, or together with other star-like glia, such as NG2 glia.

Dr. Zhou has conducted electrophysiology studies on this type of glia in hippocampus and demonstrated that they are heterogeneous in a variety of functional protein expressions, namely, ion channels, glutamate receptors and transporters. These observations together with studies by others lead to an important concept that traditionally defined astrocytes can be further divided into functionally diverse subpopulations. Therefore, similar to studied brain neuronal cells, there is also a division of labor for this category of glia for their complex brain functions.

Dr. Zhou and his coworkers are interested in the in-depth understanding of the scope of glial diversity in brain and in glial functional implications. They are attempting to understand how the diversity of this type glia coordinates with brain vasculature and impacts on energy substrates regulation. They are also interested in the studies on the integration of glial heterogeneity with functional neuronal diversity in the hippocampus and cortex, as potentially poorly understood glial roles in advanced brain functions.

To achieve these research goals, Dr. Zhou and his coworkers at the Ordway Research Institute have applied in situ and single cell electrophysiology to examine the functional glial ion channels, receptors and transporters; have employed immunocytochemical confocal and deconvolution microscopy techniques to identify diverse glial subtypes in situ and correlate their anatomic relationship with blood vessel and neurons; and have used molecular biology, e.g., RT-PCR, to identify the genes encoding these functional proteins.

Selected Publications

• Zhou M, Schols GP, Kimelberg HK (2006) Development of GLAST+ astrocytes and NG2+ glia in rat hippocampus CA1: mature astrocytes are electrophysiologilly passive. J Neurophysiol. 95:134-43.
• *Zhou M8, Kimelberg HK (2004) Expression and function of glutamate and GABA receptors in glial cells from the hippocampus. Neuronal/glial signaling , Kluwer Academic / Plenum Publishers, edited by Hatton GI and Parpura V, Chapter 5.
• Schools GP, Zhou M, Kimelberg HK, (2003) Electrophysiologically “complex” glial cells freshly isolated from the hippocampus are immunopositive for the chondroitin sulfate proteoglycan NG2. J Neurosci Res. 73:765-77.
• Zhou M, Kimelberg, HK, (2001) Freshly isolated hippocampal CA1 astrocytes comprise two populations differing in glutamate transporter and AMPA receptor expression. J. Neurosci . 21 : 7901-7908.
• Zhou M, Kimelberg HK, (2000) Freshly isolated astrocytes from rat hippocampus show two distinct current patterns and different [K + ] o uptake capabilities J. Neurophysiol . 84:2746-2757.
• Zhou M, Schools GP, Kimelberg HK, (2000) GFAP-mRNA positive glia acutely isolated from rat hippocampus predominantly show complex current patterns. Mol. Brain Res. 76:21-131.
• Seifert G, Zhou M, Steinhäuser C, (1997) Age-dependent analysis of AMPA receptor properties expressed by astrocytes of the mouse hippocampus, J. Neurophysiol , 78:2916-2923.