Describe the interplay between Ih and Ca currents that underlie bursting activity. Where is this activity found and why does it matter?
Hyperpolarizing or hyperpolarization-activated current (Ih) is an inward current that contributes to pacemaker activity of neurons. It acts between a hyperpolarizing current range of 0.1-2.0nA with an amplitude that reaches its peak activity in 2-10 seconds. Ih causes a low kinetic energy that is summative throughout the burst until its amplitude is large enough to cause the hyperpolarization of cell, thereby bringing the end to the burst process. On the other hand, Ca currents (calcium-induced inactivated currents) follow the depolarizing voltage of Aplysia neurons causing the interburst of hyperpolarization for Aplysia bursting neurons. Bursting activity is thought to be important in the operation of heart interneuron, Aplysia neuron R 15 and pacemaker neurons. It is important to know as it has a connection with the spiking activity of the cells and sagging of membrane cells that affects beating of the heart (Furhrmann, Markram, & M., 2002).
Give at least three examples of how neocortical anatomy and function are specialized. Or: Is all neocortex created equal?
During sustained current injections that take place particularly in pyramidal neurons neocortex has a decreased instantaneous discharge rate. This enables the coordinated response to currents, like forward masking, to occur. When two responses occur, cells respond to the initial response.
Neocortex has numerous, repeated duplications for stereotypical microcircuits. Each and every duplicate have different temperature requirements and hence is suitable for operations in various regions.
The structure of the neocortex can is alterable after modification of the source or pattern of activities in the thalamocortical afferents take place. It gives a possibility for one neocortical area to substitute with another, if a switch of input modality occurs during development. In any case, a newly created neocortex will be different.
What is the glomerulus in the thalamus and why do we care?
It is a knot like tiny neutral circuitry located in the thalamus and is responsible for receiving direct input from the olfactory nerves. We care about it because its failure in the thalamus makes the olfactory bulb transmit wrong senses of smell from the nose to the brain (Alexander & Yu, 2011).
What does the taxicab study tell us about hippocampal function?
The taxicab study tells us that the hippocampal volume is related to the demand for spatial navigation that increases with spatial demand activity. Spatial memory, therefore, increases with spatial demand activities when a mammalian organism engages in. The study also hypothetically suggests that ability of mammalian hippocampi to undergo structural changes, in response to behavior, requires spatial memory increases with the organism’s extensive experience within spatial navigation (Good & Gadian, 1999).
What is the effect of inhibition at the distal dendrites compared to the cell body?
Inhibition modulates spike back propagation, causing a spike amplitude reduction in the distal dendrites of a cell.
Inhibition cause direct hyperpolarization for the distal dendrites, thereby reducing transient [ca2+]i, that changes in the dendrites and is associated with dendrite’s branches.
Inhibition modulates the spike-associated [ca 2+]i changes for the distal dendrites without causing significant changes in the proximal part of the cell.
Inhibition of postsynaptic potentials invoked by simulation of the stratum lacunosum molecular reduces the amplitude of single spikes in the distal dendrites.