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HANDBOOK OF PHYSIOLOGY 



NEUROPHYSUJLOGY II 



clinical phenomena observed by the various authors, 

 there is very little disagreement about the type of 

 electrical discharges that may follow stimulation of 

 the hippocampus in man. The excellent descriptions 

 and illustrations of Cadilhac (i) show that there is a 

 tendency for prolonged rhythmic discharges in the 

 hippocampus. There seems to be a rather low thresh- 

 old in man as well as in other animals for the after- 

 discharges that follow either electrical or mechanical 

 stiiTiulation of the hippocampus, but this might vary 

 somewhat according to the extent of the histological 

 abnormalities that might be present in one patient 

 and not in another. In fact increased threshold and 

 smaller discharges have been reported by Passouant 

 et al. (i8) in two of their four hemispherectomized 

 patients; i n these two extensive hippocampal gliosis 

 was found Similar impressions have been described 

 by Pampiglione & Falconer (i6), since in their group 



of 17 patients in whom histological examination of 

 the exci.sed temporal lobe and hippocampus was 

 made, very poor discharges were evoked from the 

 hippocampus in four patients with severe sclerosis of 

 this structure. 



We may conclude this short review on some effects 

 of electrical stimulation of the hippocampus in man 

 by emphasizing that the functional significance of 

 this structure is still unknown. Various hypotheses 

 have been advanced since Ferrier (5) cautiously 

 suggested that a center for touch might be located 

 there. The detailed observations in man are sparse 

 and somewhat inconsistent, and even the contribu- 

 tion of the conscious patient who tries to transmit to 

 the observer the wealth of the subjective manifesta- 

 tions has so far failed to support the view that the 

 hippocampus might be a structure with a single, 

 definite and invariaijle function. 



REFERENCES 



1. Cadilhac, J. Hippocanipe if Epilcpsir. Montpellier: Dehan, 



'955- 



2. Caven.\gh, J. AND \. Mever. Bill. M. J. i: 1403, 1956. 



3. Chapman, VV., K. E. Livingston and J. L. Poppen. 

 J. Neurophysiol . 13: 65, 1950. 



4. Chapman, W., H. R. Schroeder, G. Gever, M. A. B. 

 Brazier, C. Faoer, J. L. Poppen, H. C. Solomon and 

 P. I. Yakovlev. Science 120: 949, 1954- 



5. Ferrier, D. The Functions of the Bruin. London : Smith, 

 Elder, 1876. 



6. Gastaut, H. J. physioL, Paris 44: 431, 195^- 



7. Glusman, M., J. Ransohoff, L. Pool and N. Sloan. 

 J. Neurophysiol. 16: 528, 1953. 



8. Green, J. D. and VV. R. .^dev. Eleclroencephaloa. & Clin. 

 Neurophysiol. 8: 245, 1956. 



9. Kaada, B. R. Acta physiol. .tcandinav. 24; 83, 1951. 



10. Kaad.a, B. R. and H. Jasper. A.M. A. Arch. .\'eurol. & 

 Psychiat. 68: 609, 1952. 



11. LiBERSON, W. T., W. B. Scoville and R. H. Dunsmore. 

 Electroencephalog. & Clin. .Neurophysiol. 3: i, 1951. 



12. Macchi, G. Arch. ital. anat. e embriol. 53: 175, 1948. 



13. Macchi, G. J. Comp. .\'eurol. 95: 245, 1951. 



14. OssiPOFF, P. Monil. Neurol. (Russe) 8: 11, 1900. 



15. Pampiglione, G. and M. A. Falconer. Electroencephalog. cF 

 Clin. .Neurophysiol. 8: 718, 1956. 



16. Pampiglione, G. and M. .\. Falconer. Colloque sur T Etude 

 Electroclinique des Troubles Psychiques Inlermittents chez les 

 Epileptiques. Reunion Europe enne d' information EEC, Marseilles, 

 15-19 Oct. 1956. To be published. 



17. P.^ssouANT, P., C. Gros, J. Cadilhac .\nd B. Vl.\ho- 

 VITCH. Rei\ neurol. 90: 265, 1954. 



18. Passouant, P., C. Gros, L. van Bogaert and J. Cadilhac. 

 Rev. neurol. 92 : 96, 1 955. 



19. Penfield, VV. .«lND T. C. Erickso.n. Epilepsy and Cerebral 

 Localization. Springfield : Thomas, 1941. 



20. Penfield, \V. .■knd H. Jasper. Epilepsy and the Functional 

 Anatomy of the Human Brain. London: Churchill, 1954. 



21. Pool, J. L. J. .\'eurosurg. 11: 45, 1954. 



22. Sloan, N., J. L. Pool and J. R.\nsohoff. Electroencepha- 

 log. & Clin. Neurophysiol. 4: 243, 1952. 



23. Spencer, VV. G. Tr. Roy. Soc, London, ser. B 185: 6og, 

 1894. 



