Dendritic mechanisms and their role in cortical learning

Apical and basal dendrites

Dendrites are small branches that extend from the main body of a neuron, and they are important for receiving and integrating inputs from other neurons. Neurons can have different types of dendrites, and recent research suggests differential roles of apical and basal dendrites in neural processing.

Figure: The dendritic tree of a layer 5 pyramidal neuron.

Apical dendrites are dendrites that extend from the top of a neuron's cell body, and they are thought to play a role in the integration of inputs from other neurons over a longer time scale. This is because apical dendrites are often much longer and more branching than basal dendrites, which allows them to receive inputs from a larger number of neurons over a wider area.

Basal dendrites, on the other hand, are dendrites that extend from the base of a neuron's cell body, and they are thought to play a role in the integration of inputs from other neurons over a shorter time scale. This is because basal dendrites are typically shorter and less branching than apical dendrites, which allows them to receive inputs from a smaller number of neurons over a more focused area.

Overall, the roles of apical and basal dendrites in neural processing are still being studied, and further research is needed to fully understand their functions and how they contribute to brain function.

Dendritic spikes

Dendritic spikes are electrical signals that are generated in the dendrites of neurons, and they have been shown to play an important role in learning and memory. Dendritic spikes are thought to be involved in the formation of new connections between neurons, a process known as synaptic plasticity, which is essential for learning and memory.

Recent research has shown that dendritic spikes are triggered by the activity of other neurons, and that they can influence the strength of the connections between neurons, known as synapses. For example, dendritic spikes have been shown to increase the excitability of neurons and to enhance the ability of synapses to change in response to activity, both of which are important for learning and memory.

Additionally, dendritic spikes have been shown to be involved in the consolidation of long-term memories, which is the process by which short-term memories are stabilized and transferred to long-term storage. This is thought to occur through a process called synaptic tagging and capture, in which dendritic spikes tag synapses that are involved in the memory, and then capture proteins that are needed for the strengthening of those synapses.