This is the description of presonal experiments, realized in 2015-2016 in the 19 lab at CINVESTAV-sur.
Each file contains a list of numbers. Those numbers represents the moment when a single detected spike reachs its maximum value of delta in voltage.
We use an arrage of 4096 micro electrodes, henceforth refered as channels, scattered in a square arrengement of 64 by 64 to obtain the extracellular record of a portion of rat hippocampus. Then, the "times" provided corresponds to a unit or cell firing into CA3 area or GD area.
The experimental procedure followed is described next.
From 350 µm submerged horizontal slices of ventral rat hippocampus, we measured the variations in voltage from all the tissue that fits into a 4 mm by 4 mm square. Especially we look the CA3 and GD areas. The experiment follows 3 stages.
Stage 1. The slice is submerged into a standard solution henceforth referred as CONTROL (mM: NaCl 129, KCl 3, MgSO4 1.8, NaH2PO4 1.25, NaHCO3 20, Glucosa 10, CaCl21.6, in presence of carbogene (95% O2, 5% CO2), at 34-36 °C and with 10-12 ml/min of steady flux). On this condition, a 4 minute register of the spontaneous activity was obtained.
Stage 2. Chemical transmission bloquers (APV 30 µM, NBQX 10 µM y bicuculin 15 µM) were added to the control solution. The slice was exposed to the new solution (called BLOQUEO) for at least 25 minutes before the register started. Keeping the previously described conditions (temperature, flux, etc.), 4 minutes to register of the spontaneous activity of the slice were recorded.
Stage 3. The final step was adding 10µM of Mefloquine (Cx36 Bloquer) to the previous solution. The spontaneous activity of the cells in the new condition called MEFLOQUINA was registered after 40 minutes of interaction between the tissue and the drug.
To obtain the presented files, the follow steps were applied to the 3 conditions described:
From the electrodes inside in the interest zone (CA, GD), we extract the spikes from the register and separate those into clusters using a non-supervised approach.
Those clusters represents a single unit (ensamble or cell) that was registered with a specific electrode, then the part of the file name "_chXXXX". The number of the channel represents the position into the matrix that is recording the unit selected. The initial part of the name "cellXXX"_indicates the isolated unit into the total counter of the register, by zone and by condition._(cell000_ch0000 into the CA folder into the BLOQUEO folder means that is the unit detected number 000, registered by the 0000 electrode, that in the BLOQUEO condition is into the CA area.)