Articles in 2011

Reinforcement learning models have provided insight into the functions of dopamine and cortico-basal ganglia-thalamo-cortical circuits. Here the authors review the literature suggesting that these models can also be applied to improving our understanding of dysfunction in this system, particularly in the context of disease.

Previous work suggests that protein kinase M zeta (PKMζ) is required for long-term memory maintenance. Here, the authors find that, under some conditions, PKMζ inhibition does not erase memory, but only temporarily disrupts the expression of memory.

Memory reactivation underlying consolidation can occur during periods of sleep or in waking where wakeful memory reactivation is susceptible to disruption. Contrary to prior predictions, the authors find that memory reactivation during slow-wave sleep immediately stabilizes memories in the absence of REM sleep.

The authors report that the rate at which calmodulin binds calcium is faster than that of other calcium binding proteins, and that calmodulin directly intercepts incoming calcium and sets [Ca²⁺]_free rather than responding to the lower [Ca²⁺]_free set by other buffers.

Szuts et al. have developed a wireless neural recording system that outperforms existing rodent telemetry systems in either channel count, weight or transmission range. They show that it can be used to record brain signals in animals outdoors and in tunnels.

Ephaptic coupling is the feedback of extracellular fields onto the electrical potential across the neuronal membrane, independent of synapses. Here, the authors report that, under physiological conditions, endogenous brain activity can affect neural function through field effects.

Combining positron emission tomography and functional magnetic resonance imaging, the authors investigate the effects of emotionally arousing music on the dopamine system. They find that the anticipation of this abstract reward can result in dopamine release in an anatomical pathway that is distinct from that associated with the peak pleasure itself.

Using genetics and pharmacology, the authors find that the dynamics of olfactory receptor neurons can be separated into two sequential steps: transduction and spike generation. They then characterize these two components.

Here the authors demonstrate that the orientation preference of a cortical column is closely related to the population receptive field of the ON and OFF thalamic inputs. These results support models suggesting that orientation maps develop on the basis of the receptive field arrangement of ON and OFF visual inputs to the cortex.

Graf et al. examine how information can be decoded from the pattern of population activity in primary visual cortex neurons. They find that the structure of neuronal response distributions, including their correlated variability, contains critical information for sensory decoding.

Aponte et al. show that optogenetic activation of a population of hypothalamic neurons expressing agouti-related peptide (AGRP) is sufficient to evoke voracious feeding behavior in mice. This feeding was not dependent on suppressing the activity of anorexigenic pro-opiomelanocortin–expressing neurons, suggesting that AGRP neurons directly engage feeding circuits.