Distress call-induced gene expression in the brain of the Indian short-nosed fruit bat, Cynopterus sphinx

Individuals in distress emit audible vocalizations to either warn or inform conspecifics. The Indian short-nosed fruit bat, Cynopterus sphinx, emits distress calls soon after becoming entangled in mist nets, which appear to attract conspecifics. Phase I of these distress calls is longer and louder, and includes a secondary peak, compared to phase II. Activity-dependent expression of egr-1 was examined in free-ranging C. sphinx following the emissions and responses to a distress call. We found that the level of expression of egr-1 was higher in bats that emitted a distress call, in adults that responded, and in pups than in silent bats. Up-regulated cDNA was amplified to identify the target gene (TOE1) of the protein Egr-1. The observed expression pattern Toe1 was similar to that of egr-1. These findings suggest that the neuronal activity related to recognition of a distress call and an auditory feedback mechanism induces the expression of Egr-1. Co-expression of egr-1 with Toe1 may play a role in initial triggering of the genetic mechanism that could be involved in the consolidation or stabilization of distress call memories

Genetic diversity and population structure of leaf-nosed bat Hipposideros speoris (Chiroptera: Hipposideridae) in Indian subcontinent

Genetic variation and population structure of the leaf-nosed bat Hipposideros speoris were estimated using 16S rRNA sequence and microsatellite analysis. Twenty seven distinct mitochondrial haplotypes were identified from 186 individuals, sampled from eleven populations. FST test revealed significant variations between populations in the overall pairwise estimation (FST = 0.710; p < 0.001). In addition, haplotype network and analysis of molecular variation analysis (AMOVA) consistently suggest the prevalence of genetic structure in the sampled populations. However, the mtDNA data was not significantly different in few closely located urban populations, but significant difference has been observed with the use of microsatellite data. The Bayesian clustering analysis identified eight clusters among the populations; the clustering pattern also corresponded to the haplotype networks. Overall, the present study suggests a "macrogeographic genetic isolation-by-distance" and possibility of gene flow among closely located populations

Molecular and Functional Characterization of Bacopa monniera

Over the last 50 years, laboratories around the world analyzed the pharmacological effect of Bacopa monniera extract in different dimensions, especially as a nerve tonic and memory enhancer. Studies in animal model evidenced that Bacopa treatment can attenuate dementia and enhances memory. Further, they demonstrate that Bacopa primarily either acts via antioxidant mechanism (i.e., neuroprotection) or alters different neurotransmitters (serotonin (5-hydroxytryptamine, 5-HT), dopamine (DA), acetylcholine (ACh), γ-aminobutyric acid (GABA)) to execute the pharmacological effect. Among them, 5-HT has been shown to fine tune the neural plasticity, which is a substrate for memory formation. This review focuses on the studies which trace the effect of Bacopa treatment on serotonergic system and 5-HT mediated key molecular changes that are associated with memory formation

Environmental enrichment improves social isolation-induced memory impairment: The possible role of ITSN1-Reelin-AMPA receptor signaling pathway.

Environmental enrichment (EE) through combination of social and non-biological stimuli enhances activity-dependent synaptic plasticity and improves behavioural performance. Our earlier studies have suggested that EE resilience the stress induced depression/ anxiety-like behaviour in Indian field mice Mus booduga. This study was designed to test whether EE reverses the social isolation (SI) induced effect and improve memory. Field-caught mice M. booduga were subjected to behaviour test (Direct wild, DW), remaining animals were housed under SI for ten days and then housed for short-term at standard condition (STSC)/ long-term at standard condition (LTSC) or as group in EE cage. Subsequently, we have examined reference, working memory and expression of genes associated with synaptic plasticity. Our analysis have shown that EE reversed SI induced impairment in reference, working memory and other accompanied changes i.e. increased level of Intersectin 1 (ITSN1), Huntingtin (Htt), Synaptotagmin -IV (SYT4), variants of brain-derived neurotrophic factor (Bdnf - III), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor (GluR1) expression, and decreased variants of Bdnf (IV), BDNF, Reelin, Apolipoprotein E receptor 2 (ApoER2), very low-density lipoprotein receptor (VLDLR), Src family tyrosine kinase (SFKs), Disabled protein (Dab)-1, Protein kinase B (PKB/Akt), GluR2, Mitogen-activated protein kinase (MAPK) and Extracellular signal-regulated kinase (ERK1/2) expression. In addition, SI induced reduction in BDNF expressing neurons in dentate gyrus of hippocampus reversed by EE. Further, we found that SI decreases small neuro-active molecules such as Benzenedicarboxylic acid, and increases 2-Pregnene in the hippocampus and feces reversed by EE. Overall, this study demonstrated that EE is effectively reversed the SI induced memory impairment by potentially regulating the molecules associated with the ITSN1-Reelin-AMPA receptor pathway to increase synaptic plasticity

Environmental enrichment reverses the social isolation induced alteration in expression of Reelin, its receptors and SFK.

(a) Representative western blot showing that expression level of Reelin (180 kDa), APoER2 (95 kDa), VLDLR (96kDa) and SFK (60 kDa). EE housing condition reversed the SI induced stress reduced the expression of (b) Reelin, (c) APoER2, (d) VLDLR and (e) SFK. Data presented as mean ± SEM [DW-Direct Wild (n = 4); STSC- Short Term at Standard Condition (n = 4); LTSC- Long Term at Standard Condition (n = 4); EE- Environmental Enrichment (n = 4)], One way ANOVA with post hoc comparisons [a: DW vs STSC; b: DW vs LTSC; c: DW vs EE; d: STSC vs LTSC; e: STSC vs EE; f: LTSC vs EE] and * indicates level of significant (**p<0.01;***p<0.001).</p

Social isolation induced alteration in expression of Bdnf variant reversed by environmental enrichment.

Bdnf variants exon-III (a) and (c) exon -IV expression pattern in mice represents different housing condition. Real-time qPCR showing the expression of (b) Bdnf exon (III) level was increased, but (d) exon (IV) level was decreased by SI stress in STSC and LTSC housing condition, EE reversed the SI effect. Data presented as mean ± SEM [DW-Direct Wild (n = 6); STSC- Short Term at Standard Condition (n = 6); LTSC- Long Term at Standard Condition (n = 6); EE- Environmental Enrichment (n = 6)], One way ANOVA with post hoc comparisons [a: DW vs STSC; b: DW vs LTSC; c: DW vs EE; d: STSC vs LTSC; e: STSC vs EE; f: LTSC vs EE] and * indicates level of significant (**p<0.01;***p<0.001).</p

Environmental enrichment reverses the social isolation induced changes in the expression of BDNF in hippocampus.

Light micrograph (40X) of hippocampus region showing the expression pattern of BDNF positive neurons (a), higher magnification (40X) of selected (b) dorsal, (c) ventral region of the box in “a” and (d) Optical density of BDNF immunoreactivity in granular layer of dorsal dentate gyrus (dDG) and ventral dentate gyrus (vDG). Scale bars: 500μm (a-c). Significant difference between dDG and vDG showing # for DW and $ for EE mice. Data presented as mean ± SEM [DW-Direct Wild (n = 4); STSC- Short Term at Standard Condition (n = 4); LTSC- Long Term at Standard Condition (n = 4); EE- Environmental Enrichment (n = 4)], One way ANOVA with post hoc comparisons [a: DW vs STSC; b: DW vs LTSC; c: DW vs EE; d: STSC vs LTSC; e: STSC vs EE; f: LTSC vs EE] and * indicates level of significant (*p<0.05;***p<0.001).</p

Environmental enrichment reverses social isolation induced alteration in expression of ITSN1 and associated signalling molecules.

(a) Representative western blots showing the expression level of ITSN1 (180 kDa), Htt (350kDa), SYT4 (44 kDa) and BDNF (32 kDa). Estimated values showed that EE significantly reversed the social isolation induced alteration in the expression of (b) ITSN1, (c) Htt, (d) SYT4 and (e) BDNF. Data presented as mean ± SEM [DW-Direct Wild (n = 6); STSC- Short Term at Standard Condition (n = 6); LTSC- Long Term at Standard Condition (n = 6); EE- Environmental Enrichment (n = 6)], One way ANOVA with post hoc comparisons [a: DW vs STSC; b: DW vs LTSC; c: DW vs EE; d: STSC vs LTSC; e: STSC vs EE; f: LTSC vs EE] and * indicates level of significant (**p<0.01;***p<0.001).</p