Reversal of 'handedness' in rats is achieved more effectively by training under peripheral than under central blockade of the preferred forepaw.
Reversal of forepaw preference was studied in rats under conditions of peripheral (bracelet) or central (inactivation of contralateral motor cortex and caudate nucleus by intracerebral injection of tetrodotoxin) preferred limb block. Persisting change of the forepaw preferred when reaching for food into a tubular feeder was achieved on the average after 91 (n = 27) and 211 (n = 26) reaches, respectively. When tested in another task (recovering food pellets from a horizontal shelf accessible through a narrow slit below the ceiling of the test box) same rats displayed identical (45%) and opposite (15%) preference or were ambidextrous (40%). Forced change of handedness on the tubular feeder task was accompanied by similar change of preference on the shelf task in only 17% rats. It is concluded that rather independent lateralisation of the two tasks reflects differential contribution of the corticospinal, rubrospinal and ventromedial motor systems. Reversal training proceeds faster with peripheral blockade which establishes not only the new preference but also inhibits the original one.
Milyaeva
E I
EI
Institute of Physiology, Czechoslovak Academy of Sciences, Prague.
Bures
J
J
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D002421:Caudate Nucleus / Q000502:physiology; D003216:Conditioning, Operant; D005552:Forelimb; D007839:Functional Laterality / Q000187:drug effects; D007858:Learning / Q000187:drug effects; D008297:Male; D009044:Motor Cortex / Q000502:physiology; D009928:Organ Specificity; D051381:Rats; D011919:Rats, Inbred Strains; D013779:Tetrodotoxin / Q000633:toxicity*
D013779:Tetrodotoxin