Dendritic integration

Jaan Aru examines biological mechanisms that may matter for consciousness, including dendritic integration and interactions between cortex and thalamus. The discussion connects these mechanisms to cognition and prospects for artificial consciousness, then explores insight and creativity across ordinary problem-solving and altered experiences.

…Abstracting the entire dendritic arbor into a single compartment thus omits useful computational properties (Poirazi et al. 2003). Three main factors contribute to the integration process: (1)

Although dendritic signaling strongly influences sensory processing and learning, the connection between dendritic integration and somatic output is still not fully understood. Our aim is maping the origins of dendritic events during different aspects of visual learning.We used 3D two-photon laser scanning microscopy with acousto-optic deflectors to simultaneously record jRGECO1a (calcium) and JEDI-2p (voltage) signals in the apical dendrites of layer 5 pyramidal cells in the primary visual cortex of mice during visual discrimination. We examined mice with controlled water access participating

Understanding dendritic integration in relation to its excitatory and inhibitory inputs is critical to deciphering neuronal data processing. Upon sensorimotor stimulus, the cerebellar Purkinje neuron (PN) receives excitatory inputs from a single climbing fiber (CF), thousands of parallel fibers (PFs), and feed-forward inhibitory inputs (FFI) from molecular layer interneurons (MLIs). This study aims to understand the dendritic interplay of MLI inhibitory inputs, shaping excitatory inputs upon air puff stimulation in awake mice.We labeled MLI axons with GCaMP6 and PN with the voltage-sensitive d

Temporal irregularity and heterogeneities are key features of neuronal spiking activity in cortical networks. Simplified theoretical models of cortical circuits show that these features can be mechanistically accounted for if cortex operates in a fluctuation-driven regime (FDR). In FDR, excitatory and inhibitory currents are approximately balanced, and activity fluctuations emerge intrinsically from the non-linear network dynamics. However, it is still unclear if cortex operates in this regime. We address this question by analyzing sub-threshold membrane potential of neurons in sensory and fr

…underlying altered hippocampal dendritic integration, degraded place coding, and deficits in spatial memory. Two-photon glutamate uncaging experiments revealed that the mechanisms constraining the generation of Na+ spikes in hippocampal 1st order pyramidal cell dendrites are profoundly degraded in experimental epilepsy. This phenomenon was reversed by selectively blocking Nav1.3 sodium channels. In-vivo two-photon imagin