|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 4. Schematic outline of the impairment of the postural system caused by UL,
and restoration of postural function in compensated lampreys. (A) Conceptual
model of the roll control system as proposed previously
(Deliagina and Pavlova, 2002).
Left and right groups of RS neurons, RS(L) and RS(R), receive vestibular (V)
and visual (E) sensory inputs. The plus and minus signs without parentheses
indicate the major effects on RS neurons produced by these inputs, the signs
in parentheses indicate the minor effects. Weaker inputs from the ipsilateral
labyrinths are shown by dotted lines. The presumed directions of rolling
caused by RS(L) and RS(R) are indicated by the white and black arrows,
respectively. (B–D) Operation of the model under different conditions.
The curves represent the activity of the left and right groups of RS neurons
as a function of roll angle. (B) Control (intact lamprey). The two activity
curves intersect, and the system has an equilibrium point at 0°
(dorsal-side-up orientation). (C) The right labyrinth removed (shown by a
shaded rectangle in A). The system has no equilibrium point. (D) The result of
vestibular compensation. Plastic changes in the postural network caused a
restoration of vestibular responses in RS(L) neurons (as a result of
augmentation of input from the ipsilateral labyrinth) and recreation of the
equilibrium point.
|
