Representation of the body in the lateral striatum of the freely moving rat: single neurons related to licking.

This study examined the relationship of single-neuron activity (n = 739), recorded from the lateral striatum of freely moving rats, to oral movements involved in licking single drops of liquid. Certain neurons (n = 74) fired specifically in relation to licking. Their firing rates increased during licking, but remained near zero in the absence of licking, throughout a full sensorimotor examination of the remainder of the orofacial area and all other body parts. Another category of neurons (n = 17) fired during licking but also fired in the absence of licking, during one or more other orofacial sensorimotor function(s). Lick-related neurons were located in the lateral striatum, throughout the entire anterior-posterior range studied (from +1.5 to -1.5 mm anterior-posterior, A-P, bregma = 0). Summed over the full A-P range, they were located significantly ventral to representations of the trunk and limbs. These findings extend the characterization of the somatotopic organization exhibited by lateral striatal neurons in the rat, to include representation of oral functions, consistent with converging evidence regarding the functional organization of the striatum.

Einfluß der ernährung bei junglarven von Myzus persicae (Sulz.) (Aphididae) auf ihre entwicklung zu geflügelten oder Ungeflügelten.

Certain plants are able to convert first stage larvae of the Green Peach Aphid into apterous larvae although the larger part of them would develop into alates if reared continuously on a holidic diet.This Apterousness Promoting Principle (ApP principle) has a greater effect on previously starved larvae and on those whose extremities were partly amputated. The ApP principle can be shown most clearly in young radish seedlings, as well as in other young plants if they are optimal hosts. It is reduced in old radish leaves and in plant species which are merely accepted by Myzus persicae for a longer time. The principle is also reduced by wilting, etiolation, or during and shortly following over-population of the young seedlings. By covering the cotyledons with a thin parafilm membrane or by washing them with water the ApP principle is partly eliminated. We suggest the ApP principle is largely coupled with "good" food, but an important component of it operates as a "token stimulus" perceived already in part on the plant surface. Hence the standard diet seems to offer "poor" nutrition. With further deterioration such as the omission of ascorbic acid or brief food deprivation the number of alates increases, whereas with extremely poor food (for example if the essential amino acid isoleucine is entirely omitted or if food is withheld for more than 18 h) this gives way to an increase in the formation of apterous larvae. A group effect may modify the reaction after brief omission of food: more of the larvae in groups develop into alates, single larvae more into apters.