Outdoor Walking Test With a Global Positioning System Device as an Additional Tool for Functional Assessment of Older Women.

The primary aim was to assess the test-retest reliability of an outdoor walking test with a global positioning system device in older women in a community setting. In addition, correlations between the suggested test and various tests recommended to evaluate muscle strength, walking speed, and self-perceived health status in older adults were studied. The study included 40 women aged 68 (SD = 5) years. The primary outcomes were total walked distance and mean walking speed. The secondary outcomes were lower-body strength, heart rate, speed in a 4-m walk test, and self-perceived health status. The intraclass correlation coefficients calculated for the total walked distance, mean walking speed, and mean heart rate were .94, .92, and .37, respectively. Thus, the suggested outdoor walking test with the application of a global positioning system device may be considered a reliable test tool, which can be recommended for the evaluation of walking ability among older women in a community setting.

Dorsal column nuclei projection to the cerebellar caudal vermis in the rabbit revealed by the fluorescent double-labeling method.

The organization of the projection from the dorsal column nuclei (DCN) to the lobules of the cerebellar caudal vermis was studied in the rabbit. Following unilateral injections of the retrograde fluorescent tracers fast blue (FB) and diamidino yellow (DY) into the pyramis (Pr) and uvula (Uv), respectively, a great number of single FB- (40%) and DY-labeled (60%) neurons were observed in the ipsilateral (79%) and contralateral (21%) DCN subdivisions. These neurons, as parents for the DCN-Pr and DCN-Uv projections, were numerous in the lateral cuneate nucleus (CuL; 84 and 74%, respectively) and in the complex of the gracile (Gr) and medial cuneate nuclei (CuM; Gr+CuM; 14 and 25%, respectively). A small percentage of the Pr projecting neurons was found in the CuM and Gr nuclei (2% in total). As regards the Uv, a rare and only ipsilateral projection arose from the CuM (1%), and no connection originated from the Gr. The distribution pattern of labeled neurons within individual subnuclei indicates that there are both separate regions and, to a great extent, common regions of the DCN-Pr and DCN-Uv projections. In these common regions, a small population of double FB+DY-labeled neurons (1.2%) was identified. Such neurons, present exclusively in the ipsilateral CuL and Gr+CuM, were the source of projection by way of axonal collaterals to the Pr and Uv simultaneously. It is suggested that the described connections may play a role in coordination of the axial and proximal forelimb muscles.

Organization of the pontocerebellar projection to the paramedian lobule and caudal vermis: a retrograde fluorescent tracer study in the rabbit.

Following paired injections of fluorescent tracers into the unilateral paramedian lobule (PML) and uvula (Uv) as well as the pyramis (Pr) and Uv, the distribution pattern of retrogradely labeled neurons in the pontine nuclei (PN) indicates a high degree of topographic organization in the pontocerebellar projection. This projection originates from neurons clustered in two groups located laterally and medially in relation to the course of the pyramidal tract fibers. The rostral part of the PN supplies the Uv, while its caudal part sends fibers to the PML and Pr. Neurons in defined regions of the individual PN project independently to the lobules under study, although there are also small regions in which neurons connected with the PML and Uv, and with the Pr and Uv, are intermingled. In spite of this, none of these neurons projects by axonal collaterals. The projection is bilateral, with an over two times contralateral dominance, and arises from the dorsolateral, paramedian, lateral, and peduncular PN. The PML and Uv receive profuse connections (45 and 43%, respectively), and the Pr receives moderate connections (12%). The involvement of the individual PN in the projection differs between the target lobules: the dorsolateral nucleus is the primary source of projection (45%), while the participation of the paramedian, lateral, and peduncular nuclei is successively smaller (25, 18, and 12%). This is the first report describing the organization of PML/Uv and Pr/Uv projections from rabbit PN. Comparisons with the same projections in other species are made and possible functions are discussed.

Topography of olivocerebellar projections to the uvula and paramedian lobule in the rabbit: comparison with other species.

The organization of projections from the inferior olive (IO) to the uvula of the vermis and the paramedian lobule (PML) of the same hemisphere in the rabbit cerebellar cortex was studied using retrograde tracers: Diamidino Yellow (DY) and Fast Blue (FB) dyes were injected unilaterally into these two targets in the same animals. The distribution patterns of DY- and FB-labeled neurons consistently detected in spatially separate regions of the contralateral IO subnuclei show that the IO-uvular and IO-PML projections display a distinct topography. The absence of double labeling indicates that no neurons project divergently to both the uvula and PML. The lateral and medial regions of the medial accessory olive and of the ventral lamina of the caudal principal olive project to the uvula and PML, respectively. Several neuronal groups at more rostral levels of the principal olive send fibers solely to the PML. The medial and lateral regions of the beta nucleus and the dorsomedial cell column supply the uvula and PML, respectively. Neurons in the dorsal cap and the ventrolateral outgrowth also tend to display this type of localization. Moreover, the caudal part of the dorsal accessory olive and the dorsal lamina of the principal olive project exclusively to the PML. The most caudal and rostral aspects of the IO do not participate in projection. Topographical relationships in the IO-uvular and IO-PML projections have not been previously demonstrated in the rabbit, and they are discussed in the context of inter-animal differences and cerebellar zonal organization. The possible functional significance of the connections is also discussed.

Axonal ramification of neurons in the nucleus reticularis tegmenti pontis projecting to the paramedian lobule in the rabbit cerebellum.

Projections of the nucleus reticularis tegmenti pontis (NRTP) to the cerebellar paramedian lobule were examined in the rabbit by means of the double fluorescent retrograde tract-tracing method. The rabbit NRTP is composed of a medial, large part comprising zones A (dorsomedial), B (central) and C (lateral), and of a lateral, small part (the processus tegmentosus lateralis; PTL). Following unilateral injections of Fast Blue (FB) into the rostral part of the paramedian lobule (rPML) and of Diamidino Yellow (DY) into the caudal part (cPML), known to receive spinal inputs from forelimb and hindlimb, respectively, substantial numbers of single labeled neurons were found in all bilateral NRTP divisions, apart from the zone C. Most projection neurons to the PML were located in the medial and medioventral regions of the zone B. Smaller numbers of projection neurons were located in the PTL, zone A and outside the zone B among fibers of the medial lemniscus. The pattern of FB and DY labeling suggested that neurons projecting to the rPML and cPML originated in common rather than separate regions within the NRTP. In addition, a small percentage (mean 1.3%) of double FB+DY labeled neurons were detected with a clear contralateral preponderance, among single labeled FB or DY cells. In spite of the rarity, all the NRTP neurons giving rise to intralobular collateral projections can be regarded as potential sources of simultaneous modulating influences upon two functional different forelimb (rPML) and hindlimb (cPML) regions. The findings have been discussed in relation to earlier studies in other species and commented on with respect to the possible functional meaning of these projections.

Branching projection of the nucleus "k" neurons to the rabbit cerebellar paramedian lobule: a retrograde fluorescent tracing study.

The nucleus "k", in the reticular core of the rabbit caudal pons, is divided into a large medial (composed of dorsal k1 and ventral k2) and a small lateral (k3) subdivision. In this study, the nucleus "k" subdivisions were examined in the rabbit with respect to projections to the cortex of rostral (rPML; face-forelimb region) and caudal (cPML; hindlimb region) paramedian lobule of the cerebellum. The retrograde fluorescent labeling method with Fast Blue (FB) and Diamidino Yellow (DY) was used. Numerous single FB or DY labeled neurons were found in defined regions of all nucleus "k" subdivisions bilaterally, with an ipsilateral preponderance. The distribution of these neurons indicated that afferents originating from different nucleus "k" subdivisions terminated in overlapping regions within the rPML and the cPML rather than in separate domains. Apart from this, double FB + DY labeled neurons (n = 104) were intermingled within a common region of single labeling, but exclusively on the ipsilateral side. Such neurons occupied predominantly the central and lateral regions of the caudal two thirds of the k1 subdivision, and were scattered in the caudal half of k2 as well as throughout the entire rostrocaudal extent of the k3 subdivision. The size of labeled perikarya varied from 20 to 40 microm in diameter. The number of neurons with branching axons was considerably lower than those with single projections to the rPML and the cPML. It amounted to about 3% in k1 and k3, and 2% in the k2 subdivision. However, this population may form an intralobular link between two somatotopically non-corresponding PML regions. The present study provides a morphological basis for further investigations for comparison with other species using both anatomical and electrophysiological methods, also with respect to other connections of the nucleus "k".

Pontocerebellar projection to the rabbit paramedian lobule by means of axonal collaterals: evidence for intralobular connections.

In this study, we utilized a double retrograde axonal tracing technique to investigate the possible existence of collateralized axonal projections from the pontine nuclei (PN) to the rostral (rPML) and caudal (cPML) parts of cerebellar paramedian lobule in the rabbit, known to be the forelimb and hindlimb regions, respectively. Following injections of fluorescent tracers Fast Blue (FB) and Diamidino Yellow (DY) within rPML and cPML, respectively, substantial numbers of FB and DY single labeled neurons were found in the dorsolateral, paramedian, lateral and peduncular pontine nuclei bilaterally with a very clearcut contralateral preponderance. No labeling was observed in the ventral pontine nucleus. Extensive areas of overlap of FB or DY labeled neurons indicated that no somatotopical relationship existed in projection from PN to the two functionally different PML target regions. In addition, a small number of double FB + DY labeled neurons was detected in the common areas of FB and DY single labeling in PN. These neurons give rise to pontocerebellar projections to rPML and cPML simultaneously by way of axonal collaterals and thus they may play a role in the coordination of unilateral forelimb and hindlimb movements.

Axonal collateral branching of neurones in the inferior olive projecting to the cerebellar paramedian lobule in the rabbit.

The double fluorescent retrograde technique was employed to examine the distribution of the inferior olive (IO) neurones projecting to the cortex of the rostral and caudal parts of the paramedian lobule (PML) in the rabbit cerebellum, known to be the face-forelimb and hindlimb receiving areas, respectively. Moreover, this technique was also used to investigate the possibility that IO projections reaching these two somatotopically non-homologous PML regions are collaterals of the same axones. No other reports have addressed this question. After non-overlapping unilateral injections of the cytoplasmic tracer fast blue (FB) and the nuclear dye diamidino yellow (DY) into the rostral and caudal PML, respectively, numerous single FB- or DY-labelled cells were found in the defined regions of the contralateral IO. These regions showed considerable overlap, apart from the dorsal accessory olive where a clear spatial separation of labelled cell groups was observed. Furthermore, double FB + DY-labelled neurones (n = 310) were seen in the medial accessory olive, the dorsal and ventral laminas of the principal olive, in the dorsomedial cell column and the beta nucleus. It suggests that IO neurones may branch to supply the two functionally different PML regions and in this way participate in the mechanisms of forelimb-hindlimb coordination.