Poster Conference for Lampreys Flashcards

1
Q

The focus on neuroscience has been to

A

understand the nervous system’s ability to perform motor tasks, such as locomotion

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2
Q

Locomotion is

A

moving from one place to another

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3
Q

How does a lamprey swim?

A

A lamprey swims by alternately the activity of motor neurons on the left and right sides of each of its spinal cord segments

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4
Q

Fictive locomotion

A

Measures different locomotor modes in lampreys by dissecting their spinal cord and put in a bath of solution to keep tissues in a viable state and electrodes placed in ventral roots to measure motor neuron output

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5
Q

It is difficult to understand the lamprey motor system as a whole

A

despite a lot of more empirical evidence beyond the fictive locomotion

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6
Q

The conceputal models

A

single cell and network model ahs been developed to understand lamprey motor system as a whole

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7
Q

The conceputal model has

A

experimentally established parameters

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8
Q

Single cell model which has

A

compartments of the soma (cell body) and dendrities which has ion channels

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9
Q

Lamprey spinal cord network (3)

A
  1. Reticuospinal neurones (RS) in brainstem excite interneurons and motor neurons
  2. This excitation descends onto this neurons which causes EINs on one side of the segment to excite MN (contract muscles) and CCINs which inhibit neurons on contralateral side (opposite)
  3. One side becomes active and other side is inactive
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10
Q

Neural mechanisms which stops one side from being active is

A

spike-frequency adapation (sAPH)

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11
Q

sAPH (3)

A

long-lasting afterhyperpolarisations that follow EIN’s spike of AP are added

makes EINs first spike interval (gap between spikes) bigger then the following ones.

Over time the gaps becomes larger allowing the neurons on contralateral side to fire loads of APs allowing to inhbit the previously active side

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12
Q

The sAPH is due to

A

calcium ions flowing into the cell with each AP which activates this calcium-dependent potassium channel

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13
Q

Simulation of kainate receptor (type of excitatory amino acid) via bath application showed

A

regular rhythmic activity alternating between two sides of network.

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14
Q

Role of AHP summation (causes sAPH)

A

Size of long-lasting AHPs in the model was reduced by lowering the conductance of KCa channels by 15,20, and 25%. Figure 4 at 30% shows that alternating burst activity progressively slowed down as KCa channel conductance decreased. Thus sAPH plays a role in burst-termination

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15
Q

Role of LINs in burst termination:

A

Inhibit CCINs mid-cycle allowing contralateral neurons to be active

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16
Q

Role of LINs in burst termination results:

A

A slower and irregular rhythm of kainite-activated bursting is produced when LINs are disconnected from the simulation of neural network in Figure 5B, contrary to Figure 5A, showing synaptic inhibition from LINs onto CCINs terminates bursting

17
Q

General Message

A

In the poster, the results of the simulation of network model are presented, which reproduces realistic outputs as it shows the same rhythmic alternating pattern as well as the same mechanisms lampreys utilize which terminates burst activity on one side of the spinal cord segment