Development of receptors for dopamine and noradrenaline in rat brain.

Hartley EJ, Seeman P.

Abstract

In order to examine the receptor basis for the development of spontaneous locomotion and for the effects of clonidine in the infant rat, we measured the densities of alpha 1-adrenoceptors, alpha 2-adrenoceptors and D2-dopamine receptors in various brain regions of the developing infant Wistar rat. The mesolimbic D2-dopamine receptors paralleled the rise in spontaneous locomotion of the infant rat. No alpha 1-adrenoceptors were detectable at birth in any of the four regions examined (mesolimbic, hippocampus, frontal cortex, and hypothalamus), thus providing no basis for the locomotor-stimulating action of clonidine in the first week of life. Mesolimbic alpha 2-adrenoceptors matured between 21 and 28 days (at which time clonidine yields its usual sedating action).

PMID:

6311588

[PubMed - indexed for MEDLINE]

Dev Psychobiol. 1983 Jul;16(4):269-86.

Locomotor-rotational movements in the ontogeny and play of the laboratory rat Rattus norvegicus.

Pellis SM, Pellis VC.

Abstract

During postnatal development, young laboratory rats, Rattus norvegicus, exhibit a variety of locomotor-rotational movements, that is, runs and jerk-jumps, in both playful and nonplayful contexts. The frequency of movement types differed between contexts. Some contexts, such as exploration and sleeping, contained spontaneously (i.e., possible eliciting stimuli were not observed) occurring jerk-jumps which varied with increasing age. In some contexts, such as social play, in which locomotor-rotational movements were elicited by observed stimuli, the frequency of jerk-jumps remained similar throughout ontogeny. During social play some locomotor-rotational movements were found to have immediate functions, such as achieving advantage over the partner during play-fighting, and as a means of terminating sensory input from the partner at the end of social contact.

PMID:

6884577

[PubMed - indexed for MEDLINE]

Prog Brain Res. 2004;143:57-66.

The maturation of locomotor networks.

Clarac F, Brocard F, Vinay L.

Source

Institut de Neurosciences Physiologiques et Cognitives-INPC, CNRS, Aix-Marseille II, 13402 Marseille, France. clarac@dpm.cnrs-mrs.fr

Abstract

In both vertebrates and invertebrates, the elaboration of locomotion, and its neural control by the central nervous system, are extremely flexible. This is due not only to the network properties of relevant sets of central neurons, but also to the active participation of mutually co-operative central and peripheral loops of neural projections and activity. In this chapter, we describe experiments in which the above concepts have been advanced by comparing locomotor properties in the adult vs. neonatal rat preparation. Data obtained from the in vivo vs. in vitro preparation, and swimming vs. walking behavior, suggest that the locomotor pattern progressively exhibited after birth corresponds to successive steps in the maturation of locomotor networks. Our work emphasises that during the late pre- and early postnatal period, three distinct neural entities--segmental sensory input, descending pathways, and motoneurons--play a key role in the maturation of locomotion and its neural control. We propose that the neonatal rat preparation is an excellent model for studying the conversion from immature to adult locomotion. Some neural controls are more clearly demonstrable in the developing animal preparation than in the adult because the latter exhibits an array of complex and redundant adaptive mechanisms.

PMID:

14653151

[PubMed - indexed for MEDLINE]

Exp Neurol. 1982 Oct;78(1):190-204.

Comparison of the effect of midthoracic spinal hemisection at birth or in adulthood on motor behavior in the adult rat.

Prendergast J, Shusterman R, Phillips T.

PMID: 7117480

[PubMed - indexed for MEDLINE]

Brain Res Dev Brain Res. 1993 Oct 15;75(2):213-22.