Suwarna Chakraborty (PhD Scholar) presented her seminar on "Neurobiological and psychological perspective of anxiety".
Maltesh (2nd year PhD Scholar) presented his PhD work presentation titled "Early Maternal Separation Stress-Induced Anxiety and Its Relation to Anterior Cingulate Cortex Functions in Processing of Emotional Tasks".
Guide: Dr Laxmi T Rao
Co-Guide: Dr Ravi Mudashetty
Kala P Nair (1st year MPhil scholar) presented the paper by Yamaguchi etal from Neuron 2013 entitled "Distinct Roles of Segregated Transmission of the Septo-Habenular Pathway in Anxiety and Fear"
The posterior septum consisting of the triangular septum (TS) and the bed nucleus of the anterior commissure (BAC) is predominantly linked with the medial habenula (MHb) and has been implicated in the control of anxiety and fear responses. However, its anatomical and functional linkage has largely remained elusive. We established a transgenic mouse model in which the TS and BAC projection neurons were visualized by GFP fluorescence and selectively eliminated by immunotoxin-mediated cell targeting.
The linkage between the TS/BAC and the MHb constitutes two parallel pathways composed of the TS-ventral MHb, the core part of the interpeduncular nucleus (IPN), and the BAC-dorsal MHb, the peripheral part of the IPN. Ablation of the TS and BAC projection neurons selectively impaired anxiety and enhanced fear responses and learning, respectively. Inputs from the TS and BAC to the MHb are thus segregated by two parallel pathways and play
specialized roles in controlling emotional behaviors.
Sunil Tripathi (2nd year PhD Scholar) presented the paper by Hartmann etal in Neuropharmacology 2012 entitled "The involvement of FK506-binding protein 51 (FKBP5) in the behavioral and neuroendocrine effects of chronic social defeat stress"
Chronic stress is increasingly considered to be a main risk factor for the development of a variety of psychiatric diseases such as depression. This is further supported by an impaired negative feedback of the hypothalamic-pituitary-adrenal (HPA) axis, which has been observed in the majority of depressed patients. The effects of glucocorticoids, the main hormonal endpoint of the HPA axis, are mediated via the glucocorticoid receptor (GR) and the mineralocorticoid receptor. The FK506-binding protein 51 (FKBP5), a co-chaperone of the Hsp90 and component of the chaperone-receptor heterocomplex, has been shown to reduce ligand sensitivity of the GR. This study aimed to investigate the function of FKBP5 as a possible mediator of the stress response system and its potential role in the development of stress related diseases. Therefore, we assessed whether mice lacking the gene encoding FKBP5 (51KO mice) were less vulnerable to the adverse effects of three weeks of chronic social defeat stress. Mice were
subsequently analyzed with regards to physiological, neuroendocrine, behavioral and mRNA expression alterations. Our results show a less vulnerable phenotype of 51KO mice with respect to physiological and neuroendocrine parameters compared to wild-type animals. 51KO mice demonstrated lower adrenal weights and basal corticosterone levels, a diminished response to a novel acute stimulus and an enhanced recovery, as well as more active stress-coping behavior. These results suggest an enhanced negative glucocorticoid feedback within the HPA axis of 51KO mice, possibly modulated by an increased sensitivity of the GR.
Anshu Kumari (2nd year PhD Scolar) presented her seminar titled "Plasticity in Amygdala and Anxiety".
She gave a clear introduction to Anxiety disorders in terms of a psychiatric disorder as well as its neurobiology. From human studies to molecular mechanisms, the evidences seemed to show that anxiety is associated with an over active Amygdala which possibly have a detrimental effect on the hippocampus mediated cognitive network.
Some of the interesting thoughts during the seminar were:
1) As anxiety prone individuals show increased Amygdala activity during presentation of happy as well as fearful images, Amygdala should not only be related to anxiety but stress response as a whole.
2) Do Amygdala on both sides act differently during anxiety.
3) Pre-exposure to mild stressors or exogenous cortisone could be benificial during a subsequent exposure.
4) Does BDNF get differentially elevated in different brain regions in response to stress?
Please share your comments
Dr. Ravikiran Kisan (3rd year PhD Scholar) presented the journal club on Effects of Yoga Versus Walking on Mood,
Anxiety, and Brain GABA Levels: A Randomized Controlled MRS Study by Streeter et al. published in THE JOURNAL OF ALTERNATIVE AND COMPLEMENTARY MEDICINE [Article Link]
Reported Conclusions: The 12-week yoga intervention was associated with greater improvements in mood and anxiety than a metabolically matched walking exercise. This is the first study to demonstrate that increased thalamic GABA levels are associated with improved mood and decreased anxiety.
The group discussed that the paper only presents benefits after one acute intervention but less than significant impact across the tonic 12 week intervention. The details of yoga postures used was not provided.