thalamic burst firing again

Author: rcoreilly

content/thalamus.md

@@ -225,7 +225,9 @@ The counter-point here is that the broad levels of synchrony in this bursting an
 
 From studies that manipulated burst activity and measured the effects on cortical targets, it is clear that bursting does indeed have the kind of excitatory impact on cortex that one might otherwise expect from a rapid sequence of excitatory inputs ([[@AlittoRathbunVandeleestEtAl19]]; [[@SwadlowGusev01]]; [[@BoshraHarrisDoughertyEtAl25]]).
 
-Therefore, putting together the properties of the T-type calcium channels and this greater downstream impact of bursting excitation, it does make sense that there would be some amount of augmented attention from bursting driven by novel inputs.
+Therefore, putting together the properties of the T-type calcium channels and this greater downstream impact of bursting excitation, it does make sense that there would be some amount of augmented attention from bursting driven by _novel_ inputs. However, because of the hyperpolarization requirement for activating the T-type channels, anytime there is any kind of sustained ongoing activity, bursting should not be a major contributor.
 
-The importance of baseline activity level in determining burst probability is illustrated by studies that compared primary sensory thalamus versus higher-order thalamic areas. One early report ([[@GuidoWeyand95]]) showed a burst probability of just under 1% in the primary visual cortex of awake, behaving cats. Interestingly, they also report that most of these occurred at the onset of visual stimulation. [[@^RamcharanGnadtSherman05]] report higher levels of bursting (10-20%) for neurons in higher-order thalamus (pulvinar and MD) than first-order sensory thalamus (LGN, VP, MGNv), in awake but barely behaving monkeys (head fixed, either sitting idle or holding a simple fixation). [[@^BoshraHarrisDoughertyEtAl25]] showed that bursting in the pulvinar in awake behaving monkeys was more likely for idle periods, but showed a small increase for attended locations.
+The importance of baseline activity level in determining burst probability is illustrated by studies that compared primary sensory thalamus (which will generally have a high level of sensory-driven activity) versus higher-order thalamic areas, which may be more sparsely activated depending on what kind of task is being performed. One early report ([[@GuidoWeyand95]]) showed a burst probability of just under 1% in the primary visual cortex of awake, behaving cats. Consistent with the above account, they also report that most of these occurred at the onset of visual stimulation.
+
+[[@^RamcharanGnadtSherman05]] reported higher levels of bursting (10-20%) for neurons in higher-order thalamus (pulvinar and MD) than first-order sensory thalamus (LGN, VP, MGNv), in awake but barely behaving monkeys (head fixed, either sitting idle or holding a simple fixation). [[@^BoshraHarrisDoughertyEtAl25]] showed that bursting in the pulvinar in awake behaving monkeys was more likely for idle periods, but showed a small increase for attended locations. Although they emphasized the effects of bursting driven by electrical stimulation, it was not clear that purely naturalistic bursting had clear behavioral implications.