Real-time decoding of arm kinematics during grasping based on F5 neural spike data

Due to copyright restrictions, the access to the full text of this article is only available via subscription.Several studies have shown that the information related to grip type, object identity and kinematics of monkey grasping actions is available in macaque cortical areas of F5, MI, and AIP. In particular, these studies show that the neural discharge patterns of the neuron populations from the aforementioned areas can be used for accurate decoding of action parameters. In this study, we focus on single neuron decoding capacity of neurons in a given region, F5, considering their functional classification, i.e. as to whether they show the mirror property or not. To this end, we recorded neural spike data and arm kinematics from a monkey that performed grasping actions. The spikes were then used as a regressor to predict the kinematic parameters. Results show that single neuron real-time decoding of the kinematics is not perfect, but reasonable performance can be achieved with selected neurons from both populations. Considering the neurons that we have studied (N:32), non-mirror neurons seem to act as better single-neuron decoders. Although it is clear that population-level activity is needed for robust decoding, single-neuron decoding capacity may be used as a quantitative means to classify neurons in a given region

The effect of S427F mutation on RXRα activity depends on its dimeric partner

RXRs are nuclear receptors acting as transcription regulators that control key cellular processes in all tissues. All type II nuclear receptors require RXRs for transcriptional activity by forming heterodimeric complexes. Recent whole-exome sequencing studies have identified the RXRα S427F hotspot mutation in 5% of the bladder cancer patients, which is always located at the interface of RXRα with its obligatory dimerization partners. Here, we show that mutation of S427 deregulates transcriptional activity of RXRα dimers, albeit with diverse allosteric mechanisms of action depending on its dimeric partner. S427F acts by allosteric mechanisms, which range from inducing the collapse of the binding pocket to allosteric stabilization of active co-activator competent RXRα states. Unexpectedly, RXR S427F heterodimerization leads to either loss- or gain-of-function complexes, in both cases likely compromising its tumor suppressor activity. This is the first report of a cancer-associated single amino acid substitution that affects the function of the mutant protein variably depending on its dimerization partner. This journal is © The Royal Society of Chemistry