Episodic memory, the conscious recollection of past events, is typically experienced from a first-person (egocentric) perspective. The hippocampus plays an essential role in episodic memory and spatial cognition. Although the allocentric nature of hippocampal spatial coding is well understood, little is known about whether the hippocampus receives egocentric information about external items. We recorded single units of rats from the lateral (LEC) and medial (MEC) entorhinal cortex, the two major inputs to the hippocampus. Many LEC neurons showed tuning for egocentric bearing of external items, whereas MEC cells tended to represent allocentric bearing. These results demonstrate a fundamental dissociation between the reference frames of LEC and MEC neural representations.

The complementary processes of pattern completion and pattern separation are thought to be essential for successful memory storage and recall. The dentate gyrus (DG) and proximal CA3 (pCA3) regions have been implicated in pattern separation, in part through extracellular recording studies of these areas. However, the DG contains two types of excitatory cells: granule cells of the granule layer and mossy cells of the hilus. Little is known about the firing properties of mossy cells in freely moving animals, and it is unclear how their activity may contribute to the mnemonic functions of the hippocampus. Furthermore, tetrodes in the dentate granule layer and pCA3 pyramidal layer can also record mossy cells, thus introducing ambiguity into the identification of cell types recorded. Using a random forests classifier, we classified cells recorded in DG (Neunuebel and Knierim, 2014) and pCA3 (Lee et al., 2015) of 16 male rats and separately examined the responses of granule cells, mossy cells, and pCA3 pyramidal cells in a local/global cue mismatch task. All three cell types displayed low correlations between the population representations of the rat's position in the standard and cue-mismatch sessions. These results suggest that all three excitatory cell types within the DG/pCA3 circuit may act as a single functional unit to support pattern separation.

The penetration of albendazole sulphoxide, the principal metabolite of albendazole into hydatid cysts (E granulosus) was measured by means of in vitro animal and clinical studies. The drug freely diffuses across the parasitic membranes. Cyst/serum concentrations of 22% were achieved in patients, longer pre-operative therapy produced higher concentrations.The medical treatment of hydatid disease is a recent and fast developing area. The first drug which was shown to be active was mebendazolel but it is probably of limited clinical value.2 3 Mebendazole is an extremely insoluble drug and the serum and cyst concentrations that can be achieved are of the order of 100 and 1 jsg/l respectively.i6 Concentrations of the hydroxymetabolite of mebendazole are higher6 but this is thought to be inactive (personal communication). We have reported encouraging clinical and animal7-9 results using albendazole-another benzimidazole carbamate. The postulated reason for this is that albendazole achieves much higher concentrations of one of its principal metabolites albendazole sulphoxidel(' which is believed to be the active agent. "l The aim of this study was to investigate the penetration of albendazole sulphoxide into hydatid cysts in vitro, in an animal model and in patients undergoing elective operations. We believe that these data are essential, together with the results of in vitro therapy studies'l in order that the optimal dosage and length of therapy may be designed. Methods CYSTSIn vitro cyst entry Three types of cyst were studied-human daughter cysts, small (1 mm) cyst masses from gerbil intraperitoneal infections, and single larger gerbil cysts

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