Preserved spatial coding in hippocampal CA1 pyramidal cells during reversible suppression of CA3c output: evidence for pattern completion in hippocampus.

نویسندگان

  • S J Mizumori
  • B L McNaughton
  • C A Barnes
  • K B Fox
چکیده

Medial septal modulation of hippocampal single-unit activity was examined by assessing the behavioral and physiological consequences of reversibly inactivating the medial septum via microinjection of a local anesthetic (tetracaine) in freely behaving rats trained to solve a working memory problem on a radial maze. Reversible septal inactivation resulted in a dramatic, but temporary (15-20 min), impairment in choice accuracy. In addition, movement-induced theta (theta) modulation of the hippocampal EEG was eliminated. Septal injection of tetracaine also produced a significant reduction in location-specific firing by hilar/CA3c complex-spike cells (about 50%), with no significant change in the place-specific firing properties of CA1 complex-spike units. The mean spontaneous rates of stratum granulosum and CA1 theta cells were temporarily reduced by about 50% following septal injection of tetracaine. Although there was a significant reduction in the activities of inhibitory interneurons (theta cells) in CA1, there was no loss of spatial selectivity in the CA1 pyramidal cell discharge patterns. We interpret these results as support for the proposal originally put forth by Marr (1969, 1971) that hippocampal circuits perform pattern completion on fragmentary input information as a result of a normalization operation carried out by inhibitory interneurons. A second major finding in this study was that location specific firing of CA1 cells can be maintained in the virtual absence of the hippocampal theta-rhythm.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Effect of Coenzyme Q10 (ubiquinone) on hippocampal CA1 pyramidal cells following transient global ischemia/reperfusion in male wistar rat

Ischemia/Reperfusion (I/R)-induced cerebral injury has been reported as a leading cause of deathand long-term disabilities. Hippocampus is an area which is more sensitive to be affected by I/Rand hypoxic conditions. Coenzyme Q10 is a strong antioxidant which plays a role in membranestabilization. This study aims to investigate the possible role of CoQ10 in ameliorating thehistomorphological cha...

متن کامل

Effects of Ginkgo biloba extract on the structure of Cornu Ammonis in aged rat: A morphometric study

Objective(s):Growing evidence indicates that extract of Ginkgo biloba (EGb) attenuates hippocampal-dependent memory deficit in aged individuals; however, very little is known about the effect of EGb on the structure of hippocampus. Therefore we examined the EGb-induced morphological changes of the Cornu Ammonis (CA) region in aged rats. Materials and Methods: Sixteen aged male Wistar rats, 24 ...

متن کامل

The hippocampal CA3 network: an in vivo intracellular labeling study.

The intrahippocampal distribution of axon collaterals of individual CA3 pyramidal cells was investigated in the rat. Pyramidal cells in the CA3 region of the hippocampus were physiologically characterized and filled with biocytin in anesthetized animals. Their axonal trees were reconstructed with the aid of a drawing tube. Single CA3 pyramidal cells arborized most extensively in the CA1 region,...

متن کامل

A Stereological Study on Hippocampal Subfields Following Administration of Methamphetamine in Male Mice

Background and Aims: This study examined sub-chronic effects of Methamphetamine (METH) on the stereological parameters in the Cornu Ammonis (CA) of the hippocampus in adult mice. Materials and Methods: Fifteen adult male mice, eight weeks old, were randomly divided into three groups: receive saline (controls), or low-dose (LD) 2.5 mg/kg METH, or high-dose (HD) 25 mg/kg METH, via daily intrap...

متن کامل

Effect of repeated transcranial magnetic stimulation during epileptogenesis on spontaneous activity of hippocampal CA1 pyramidal neurons in rats

Introduction: Considering the antiepileptogenic effects of repeated transcranial magnetic stimulation (rTMS), the effect of rTMS applied during amygdala kindling on spontaneous activity of hippocampal CA1 pyramidal neurons was investigated. Materials and Methods: A tripolar electrode was inserted in basolateral amygdala of Male Wistar rats. After a recovery period, animals received daily kindl...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • The Journal of neuroscience : the official journal of the Society for Neuroscience

دوره 9 11  شماره 

صفحات  -

تاریخ انتشار 1989