Sensory gating and its modulation by cannabinoids: electrophysiological, computational and mathematical analysis

Gating of sensory information can be assessed using an auditory conditioning-test paradigm which measures the reduction in the auditory evoked response to a test stimulus following an initial conditioning stimulus. Recording brainwaves from specific areas of the brain using multiple electrodes is helpful in the study of the neurobiology of sensory gating. In this paper, we use such technology to investigate the role of cannabinoids in sensory gating in the CA3 region of the rat hippocampus. Our experimental results show that application of the exogenous cannabinoid agonist WIN55,212-2 can abolish sensory gating. We have developed a phenomenological model of cannabinoid dynamics incorporated within a spiking neural network model of CA3 with synaptically interacting pyramidal and basket cells. Direct numerical simulations of this model suggest that the basic mechanism for this effect can be traced to the suppression of inhibition of slow GABAB synapses. Furthermore, by working with a simpler mathematical firing rate model we are able to show the robustness of this mechanism for the abolition of sensory gating.

The grey zone: the 'ordinary' violence of extraordinary times

The article analyses the 'ordinary' violence of revolutionary politics, particularly acts of gendered and sexual violence that tend to be neglected in the face of the 'extraordinariness' of political terror. Focusing on the extreme left Naxalbari movement of West Bengal, it points to those morally ambiguous 'grey zones' that confound the rigid distinctions between victim and victimizer in insurrectionary politics. Public and private recollections of sexual and gender-based injuries by women activists point to the complex intermeshing of different forms of violence (everyday, political, structural, symbolic) across 'safe' and 'unsafe' spaces, 'public' and 'private' worlds, and communities of trust and those of betrayal. In making sense of these memories and their largely secret or 'untellable' nature, the article places sexual violence on a continuum of multiple and interrelated forces that are both overt and symbolic, and include a society's ways of mourning some forms of violence and silencing others. The idea of a continuum explores the 'greyness' of violence as the very object of anthropological inquiry.