Apical dendrites

Anatomically segregated apical and basal dendrites of pyramidal neurons receive functionally distinct inputs, but it is unknown if this results in compartment-level functional diversity. Hippocampal place cells exhibit representational drift (Ziv et al., 2013), but this has only been characterized with somatic recordings. While dendritic activity is implicated in the formation of stable place fields and shaping hippocampal activity, in vivo studies of hippocampal dendritic activity have largely been confined to basal dendrites (Sheffield and Dombeck, 2015) or small cross-sections of apical den

…suggests that top-down input to the apical dendrites of pyramidal cells may provide a solution to this deep credit assignment problem. Experiments have shown that dendritic-spike-dependent plasticity is promoted by top-down excitatory inputs carrying information about learning targets, and it is suppressed by lateral feedback inhibition. However, exist

Artificial recurrent neural networks (RNNs) are difficult to train due to their tendency towards instability, and common training algorithms that tame such networks are not biologically plausible, i.e., back-propagation through time (BPTT). Node perturbation learning in combination with local Hebbian weight updates has been shown to approximate BPTT [1] and, thus, could achieve similar performance while being biologically plausible. However, where these perturbations could arise from and how they are utilized within neurons remains obscure. For years, the neuroscientific community has known ab

Pyramidal neurons have prominent apical dendrites that are hypothesised to modulatesomatic output. In the visual cortex, apical dendrites may receive contextual signals via top-down inputs and local inhibition. It is not known, however, what causal effects they play indriving or suppressing somatic activity, and how they shape a neuron’s visual tuning.We recorded activity of pyramidal neurons sparsely expressing GCaMP7s in layer 5 of visualcortex in awake mice before and after pruning their apical dendrites with two-photondendrotomy. Together with the neuron’s receptive field and orientation/d

…sufficient to influence the growth of dendrites and axons in cortical neurons. When activated, Gq-coupled hM3Dq leads to depolarization by increasing intracellular calcium levels. We biolistically transfecte

Pyramidal neurons have apical dendrites that are both physically and electrically segregated from their cell bodies. In sensory cortex, these apical dendrites receive primarily top-down signals from associative and motor regions, while the cell bodies and nearby dendrites of these same pyramidal neurons are mostly targeted by bottom-up or locally recurrent inputs from the sensory periphery. Due to these differences, a number of theories in computational neuroscience postulate a unique role for apical dendrites in shaping sensory processing and plasticity in the face of new or surprising stimul

…these two streams at their basal and apical dendrit

Synaptic plasticity is believed to be a key physiological mechanism for learning. It is well-established that it depends on pre and postsynaptic activity. However, models that rely solely on pre and postsynaptic activity for synaptic changes have, to date, not been able to account for learning complex tasks that demand hierarchical networks. Here, we show that if synaptic plasticity is regulated by high-frequency bursts of spikes, then neurons higher in the hierarchy can coordinate the plasticity of lower-level connections. Using simulations and mathematical analyses, we demonstrate that, when

Synaptic plasticity is believed to be a key physiological mechanism for learning. It is well-established that it depends on pre and postsynaptic activity. However, models that rely solely on pre and postsynaptic activity for synaptic changes have, to date, not been able to account for learning complex tasks that demand hierarchical networks. Here, we show that if synaptic plasticity is regulated by high-frequency bursts of spikes, then neurons higher in the hierarchy can coordinate the plasticity of lower-level connections. Using simulations and mathematical analyses, we demonstrate that, when