TY - JOUR

T1 - Postural performance in decerebrated rabbit

AU - Musienko, P. E.

AU - Zelenin, P. V.

AU - Lyalka, V. F.

AU - Orlovsky, G. N.

AU - Deliagina, T. G.

N1 - Funding Information: This work was supported by grants from NIH R01 NS-049884, the Swedish Research Council (no. 11554), and Gösta Fraenckels Foundation to TGD.

PY - 2008/6/26

Y1 - 2008/6/26

N2 - It is known that animals decerebrated at the premammillary level are capable of standing and walking without losing balance, in contrast to postmammillary ones which do not exhibit such behavior. The main goals of the present study were, first, to characterize the postural performance in premammillary rabbits, and, second, to activate the postural system in postmammillary ones by brainstem stimulation. For evaluation of postural capacity of decerebrated rabbits, motor and EMG responses to lateral tilts of the supporting platform and to lateral pushes were recorded before and after decerebration. In addition, the righting behavior (i.e., standing up from the lying position) was video recorded. We found that, in premammillary rabbits, responses to lateral tilts and pushes were similar to those observed in intact ones, but the magnitude of responses was reduced. During righting, premammillary rabbits assumed the normal position slower than intact ones. To activate the postural system in postmammillary rabbits, we stimulated electrically two brainstem structures, the mesencephalic locomotor region (MLR) and the ventral tegmental field (VTF). The MLR stimulation (prior to elicitation of locomotion) and the VTF stimulation caused an increase of the tone of hindlimb extensors, and enhanced their responses to lateral tilts and to pushes. These results indicate that the basic mechanisms for maintenance of body posture and equilibrium during standing are present in decerebrated animals. They are active in the premammillary rabbits but need to be activated in the postmammillary ones.

AB - It is known that animals decerebrated at the premammillary level are capable of standing and walking without losing balance, in contrast to postmammillary ones which do not exhibit such behavior. The main goals of the present study were, first, to characterize the postural performance in premammillary rabbits, and, second, to activate the postural system in postmammillary ones by brainstem stimulation. For evaluation of postural capacity of decerebrated rabbits, motor and EMG responses to lateral tilts of the supporting platform and to lateral pushes were recorded before and after decerebration. In addition, the righting behavior (i.e., standing up from the lying position) was video recorded. We found that, in premammillary rabbits, responses to lateral tilts and pushes were similar to those observed in intact ones, but the magnitude of responses was reduced. During righting, premammillary rabbits assumed the normal position slower than intact ones. To activate the postural system in postmammillary rabbits, we stimulated electrically two brainstem structures, the mesencephalic locomotor region (MLR) and the ventral tegmental field (VTF). The MLR stimulation (prior to elicitation of locomotion) and the VTF stimulation caused an increase of the tone of hindlimb extensors, and enhanced their responses to lateral tilts and to pushes. These results indicate that the basic mechanisms for maintenance of body posture and equilibrium during standing are present in decerebrated animals. They are active in the premammillary rabbits but need to be activated in the postmammillary ones.

KW - Balance

KW - Decerebrated rabbit

KW - Mesencephalic locomotor region

KW - Posture

KW - Sensory-motor integration

KW - Ventral tegmental field

UR - http://www.scopus.com/inward/record.url?scp=41949114266&partnerID=8YFLogxK

U2 - 10.1016/j.bbr.2008.02.011

DO - 10.1016/j.bbr.2008.02.011

M3 - Article

C2 - 18359100

AN - SCOPUS:41949114266

VL - 190

SP - 124

EP - 134

JO - Behavioural Brain Research

JF - Behavioural Brain Research

SN - 0166-4328

IS - 1

ER -