cDNA microarray analysis of gene expression in anxious PVG and SD rats after cat-freezing test

Abstract

To identify genes involved in the development of anxiety or fear, we analyzed the gene expression profiles of the cortex of anxious hooded PVG and Sprague-Dawley (SD) rats after exposure to the cat-freezing test apparatus. These two rat strains showed a marked difference in the extent of anxious behavior on the cat-freezing test; the hooded PVG rats showed highly anxious behavior while a low anxiety state was observed in SD rats. A cDNA microarray consisting of 5,931 genes was employed to investigate the global mRNA expression profiles of anxiety-related genes. According to the assumption that an abundance ratio of > or =1.5 is indicative of a change in gene expression, we detected 16 upregulated and 38 downregulated genes in PVG hooded and SD rats. Some of these genes have not yet been associated with anxiety (e.g. FGF), while other genes were recently found to be expressed in an anxious state (e.g., rat nerve growth factor-induced gene, NGFI-A). Our study also focused on the expression of some neurotransmitter receptors that have already been proven to be relevant to anxiety or fear, e.g., gamma-aminobutyric acid (GABA), cholecystokinin (CCK) and 5-HT(3) receptors. To further confirm the microarray data, the mRNA expressions of three genes: rat activity-regulated cytoskeleton-associated gene (Arc), rat NGFI-A gene and rat 5-HT(3) receptor (5-HT(3)R) mRNA, were studied by reverse transcription-polymerase chain reaction (RT-PCR). The results of RT-PCR were basically consistent with those from cDNA microarray. Our study therefore demonstrated that the microarray technique is an efficient tool for analyzing global expression profiles of anxiety-related genes, which may also provide further insight into the molecular mechanisms underlying the states of anxiety and fear.

Normal gut microbiota modulates brain development and behavior

“…Previous molecular and behavioral studies have implicated the immediate-early gene, nerve growth factor-inducible clone A (NGFI-A), and the synaptic plasticity-related gene, brain-derived neurotrophic factor (BDNF), in the development of anxiety-like behavior (15)(16)(17). We therefore studied the expression of these genes in the frontal cortex, striatum, amygdala, and hippocampus of GF and SPF mice, by means of in situ hybridization technique.…”

Identifying Genes in Monoamine Nuclei that may Determine Stress Vulnerability and Depressive Behavior in Wistar–Kyoto Rats

“…Differences in gene expression in LC or DR neurons could underlie differential responses of these systems to stress and account for the stress-sensitive phenotype of the WKY strain. Microarrays provide a powerful tool for analysis of gene expression between two different samples and have been used previously to investigate strain differences in gene expression (Farook et al, 2001;Wang et al, 2003). Therefore, the present study used microarray technology to examine strain differences in gene expression in the LC and DR of the stress-sensitive, WKY rat vs Sprague-Dawley (SD) outbred control rat.…”

Differential roles for Nr4a1 and Nr4a2 in object location vs. object recognition long-term memory

“…Two CREB-dependent immediate early genes that have been implicated in LTM are Nr4a1 and Nr4a2 (Pena de Ortiz et al 2000; von Hertzen and Giese 2005a,b;Colon-Cesario et al 2006). Nr4a1 (Nur77) and Nr4a2 (Nurr1) are members of the nuclear steroid/thyroid hormone receptor superfamily that bind in an apparently ligand-independent manner to Nerve Growth Factor1-B (NGFI-B) response elements (Baker et al 2003;Wang et al 2003).…”

“…Two CREB-dependent immediate early genes that have been implicated in LTM are Nr4a1 and Nr4a2 (Pena de Ortiz et al 2000; von Hertzen and Giese 2005a,b;Colon-Cesario et al 2006). Nr4a1 (Nur77) and Nr4a2 (Nurr1) are members of the nuclear steroid/thyroid hormone receptor superfamily that bind in an apparently ligand-independent manner to Nerve Growth Factor1-B (NGFI-B) response elements (Baker et al 2003;Wang et al 2003).Expression of both Nr4a1 and Nr4a2 has been shown to increase in the hippocampus following learning. Nr4a1 expression increased in the CA1 region of the hippocampus during context shock memory consolidation, and Nr4a2 increased in CA1 and CA3 pyramidal cell layers of the rat hippocampus following a spatial discrimination task (Pena de Ortiz et al 2000; von Hertzen and Giese 2005a,b;Keeley et al 2006;Hawk and Abel 2011).…”