EN
INTRODUCTION: Theta rhythm is one of the brain rhythms’ patterns, which are evidence for neuronal synchrony. This pattern of rhythmic activity is related to sensorimotor integration, mnemonic functions, or spatial orientation and navigation. However, it is also linked to pathological conditions, for instance: Alzheimer’s disease, post‑traumatic stress disorder, and depression. In the last decade, we discovered that the posterior hypothalamic area (PHa) is not only a modulator of brainstem information going to the hippocampus, but also is capable of generating theta rhythm independently. AIM(S): The aim of the present study was to determine if NMDA (N-Methyl-D-aspartic acid) is capable of eliciting well-synchronized theta activity in PHa preparations. METHOD(S): The study was performed on 40 PHa slices prepared from 20 male Wistar rats. Each animal was anesthetized with isoflurane and decapitated. The PHa slices were dissected and transferred into the recording chamber, perfused with artificial cerebrospinal fluid, and treated with NMDA (300 µM) and D-AP5 (D‑(–)‑2‑amino‑5‑phosphonopentanoic acid) (200 µM). The field recordings were performed with glass electrodes filled with 2.0 M sodium acetate. RESULTS: Perfusions of PHa slices with 300 µM NMDA resulted in well-synchronized theta episodes which were blocked after the path application of 200 µM D‑AP5. CONCLUSIONS: The present data shows that excitation of NMDA-type glutamatergic receptors in PHa neural networks leads to the generation of local theta rhythms. FINANCIAL SUPPORT: Supported by NCN grant no. 2017/25/B/NZ4/01476.