The ground reaction forces of postural adjustments during skilled reaching in unilateral dopamine-depleted hemiparkinson rats.

Rats with unilateral dopamine (DA) depletions (hemiParkinson analogue rats) produced by intracerebral 6-hydroxydopamine injection are impaired in using the contralateral (bad) limbs for postural adjustments. This article examines whether the bad limbs are impaired in applying the forces required to initiate postural adjustments that anticipate and accompany voluntary movements. The rats were trained to reach for food using their good paw while standing on small platforms, each of which measured force changes produced by an individual limb. In one condition the force platforms were aligned to support the limb placement of normal rats and in the second they were aligned to permit the DA-depleted rats to use a compensatory reaching stance. It was found that the bad limbs of the DA-depleted rats produced normal supporting reactions but did not initiate adjustments in posture. Postural adjustments were initiated with the good limbs and preceded rather than accompanied the reaching movements. When constrained to use the posture of normal rats, the DA-deplete rats could not reach successfully, but when allowed to adjust their stance to increase reliance on the good limbs, reaching performance improved. Measures of ground reaction forces confirm that DA-depleted rats can support posture but cannot initiate postural adjustments with their impaired limbs.

An optic-fiber photocell detector for measuring tongue protrusion in the rat: evaluation of recovery from localized cortical lesions.

A technique for measuring tongue protrusion during licking by rats is described. Liquid is automatically dispensed onto a shelf in front of the rats' cage. An array of 16 optic fibers spaced at 1 mm intervals act as photo detectors to measure tongue protrusion. The fibers activate relays connected to a microcomputer that counts individual beam breaks. The system permits the measurement of large numbers of consecutive tongue protrusions during training and testing of control and brain-damaged rats. It is shown that ventral frontal cortical lesions disrupt tongue protrusion more severely than posterior neocortex removal or dorsal frontal ablations. Complete frontal cortex lesions permit no sparing or recovery of tongue protrusion.

Effect of aluminum chloride and zinc sulfate on Autographa california nuclear polyhedrosis virus (ACNPV) replication in cell culture.

When IPL-SF-21AE III continuous insect cell line was grown and maintained in IPL-41 insect cell culture medium supplemented with 16 microM of AlCl3 or 0.24 microM of ZnSO4 . 7H2O, or both metallic salts, and then infected with Autographa california nuclear polyhedrosis virus, virus replication was increased significantly. The yield of polyhedral inclusion bodies (PIB) was enhanced up to 121%. Synthesis of cell-free nonoccluded virus was increased to 365% when infectivity was assayed by the plaque method. Newly applied electron microscopic quantitation and stereological techniques also revealed a significant increase in virus particles (VP) and in amount and size of PIB as well as number of VP per PIB.

Gypsy moth cell lines divergent in viral susceptibility. I. Culture and identification.

A series of cell lines unique in insect virus susceptibility pattern have been isolated from the ovaries of the gypsy moth (Lymantria dispar: Lepidoptera: Lymantriidae) on a synthetic medium with mammalian and avian serum supplementation. Growth curves showed the poorest growth occurring on peptone-based media with somewhat better growth on amino-acid-based media. The best growth was obtained with combined media. Serological study distinguished the present cell lines from one another and from cell lines derived from other insect species grown routinely in the same laboratory. Baculovirus susceptibility among the new lines varied from no response to a specific complete replication response upon challenge by the homologous (gypsy moth) nuclear polyhedrosis virus.

The establishment of two cell lines from the insect Spodoptera frugiperda (Lepidoptera; Noctuidae).

The history and characteristics of two cells lines developed from primary explants of pupal tissue from the insect, Spodoptera frugiperda (J.E. Smith), are described. One cell line, IPLB-SF 21, was developed with hemolymph-supplemented medium and has been maintained continuously on the medium. The second cell line, IPLB-SF-1254, was developed with a medium containing a combination of vertebrate sera plus hemolymph and was adapted to hemolyphn-free medium at the 6th passage. The IPLB-SF-21 cell line has a population doubling time of 26 to 30 hr; the doubling time of the IPLB-SF-1254 line is 36 hr. The chromosomal morphology and distribution was typical of other lepidopteran cell lines. Serological studies showed that both cell lines have at least one antigen which also is common is tissue antigens from pupae of Spodoptera frugiperda.