15. V, 1966 Speeialia 315 chromatography or by thin layer chromatography and identified, using a standard as reference. Lipids were stained with Rodamine 6G, and photographed under UV- light. Furthermore, lecithin and lysolecithin were identi- fied with the test for choline n. Reagents used were prod- ucts of Carlo Erba RS for chromatography; standards for lipids were supplied by Sigma. Results. In the experiments reported it is shown that, during aseptic autolysis, phospholipids are destroyed in the same way (qualitatively) in heart and liver, while kidney seems to behave differently. The partial disap- pearance of lecithins and phosphatidilethanolamine and cardiolipin (diphosphatidilglyceride) and the contem- porary appearance of lysolecithin and other lyso com- pounds can be seen: this appearance is much better Paper chromatograms according to MARINETTI to illustrate the dif- fereneer in phospholipid composition of normal and autolytic rabbit tissues. The chromatogram was stained with Rodamine 6 G and photographed under UV-light. Spots I and 2 belong to heart phos- pholipid, 3 and 4 to kidney, and 5 and 6 to liver. Spots 1, 3, and 5 are phospholipid of normal tissue: the nrore polar component, the dark, spread-out spot at the top is eardiolipin; below cardiolipin the two light spots arc from phosphatidilethanolamine and lecithin; the lower spots are in tim region of sphingomyelin and phospha- tidilinositol, but for these components there is much disagreement in the literature. Spots 2, 4, and 6, from the bottom upwards, are lysoleeithin, lysophosphatidilethanolamine (in the area of phospha- tidilinositol and sphingomyelin), lecithin, a non-identified spot, and eardiolipln. On the solvent front are migrated neutral lipid. demonstrated by the specific test not reported here for the amino groups and for choline. The controls, made bv incubating phospholipid from normal tissue and phospho- lipid standard in the same condition of tissue in autolysis, show a partial destruction of cardiolipin and phosphatidil- ethanolamine (but not as clearly as in tissues in autolysis), and do not show destruction of lecithin, as we have, obviously, with lecithinase in the same way as during autolysis. From non-published data we found that there is a remarkable liberation of fatty acids and the quantity of these recovered is stoichiometrically superior to disap- peared lecithin, and may partly come from hydrolysis of phosphatidilethanolamine and cardiolipin, or partly from hydrolysis of triglycerides of tissues. In the liver, the amounts of lysolecithin formed is equal to the lecithin that disappears, and the activity is higher than in kidney and heart. We can therefore say that during autolysis there is a phospholipase A activity in all three organs compared with the endogenous lecithin ; we cannot yet say, however, that there is a hydrolytic activity against phosphatidil- ethanolamine and cardiolipin, because of their break- down, as already mentioned, in the medium used for autolysis. This is only a preliminary note, but we can anticipate that aseptic autolysis could be a good method for studying the pathways of endogenous lipid catabolism 12. Riassunto. Gli autori hanno studiato il comportamento dei fosfolipidi durante l'autolisi aseptica di cuore, renee fegato di coniglio. Dai risultati ottenuti concludono che si ha attivit~ fosfolipasica in tutti e tre gli organi conside- raft verso le lecitine endogene del tessuto, attivit~ difficil- mente evidenziabile in vivo con altre tecniche. A. CAsu, M. QUERClO, and B. MODENA Istituto di Patologia Generale dell'Universit& Genova (Italy), December 13, 1965. n G. ROUSER, A. J. BAUMAN, G. KRITCHEV/SKY, D. HELLER, and J. S. O'BRIEN, J. Am. Oil Chem. Soe. 38, 54r (1961). 12 The present research has been supported by a grant from the C.N.R. Excitation of Sham Rage Behaviour by Con- trolled Electrical Stimulation of Group I Muscle Afferents I It is generally assumed that group I muscle afferents exclusively project onto segmental levels of the spinal cord and the cerebellum2, with the possible exception of group I afferents from the forelimb which seem to project to the motor cortex as well 3. In support of this opinion, high rate stimulation of group I fibres of the hamstring nerve could not induce electrocorticographic or beha- vioural arousal of intact unrestrained cats, nor could it discharge reticular units ~. Since it is known that different effects may be obtained by working on preparations with different excitability backgrounds, we have tested muscle afferent stimulation in the acute decorticate animal. Results. In 20 acute decorticate cats, 0.1 msec, 100-600 c/sec rectangular pulses were delivered to the central stump of a cut hamstring nerve through a bipolar collar- type electrode carrier, the proximal electrode being always the cathode. The stimulus threshold for the most excitable group I fibres was periodically checked by CRO monitor- ing from the sciatic trunk above the entrance of the ham- string nerve, and found to remain constant throughout the whole experiment. Stimulating voltages were always indicated as multiples of this threshold voltage (T mean- ing times threshold).