It is known that the characteristics of spontaneous and evoked neuronal activity undergo changes over time. Typically, these changes are studied in acute and subacute experimental settings (e.g., pharmacological anesthesia, sleep-wake cycles). Long-term (weeks to months) recording of activity from identified neurons presents considerable methodological challenges. Consequently, questions regarding whether such changes occur, their nature, and their impact on the functional properties of neurons and neuronal populations require further investigation. To our knowledge, such studies at the level of olfactory bulb (OB) neurons—particularly in relation to the perception of ultra-low-concentration odorants—have not been conducted to date. The aim of this work was to perform a longitudinal study of the characteristics of spontaneous and evoked activity (triggered by presentation of sulcatone vapor at ultra-low concentration, ~1 × 10 g/cm) in identified mitral/bundle (M/B) neurons of the OB. To achieve this, M/B neuron activity in the OB was periodically recorded (no more than once weekly) under xylazine-tiletamine-zolazepam anesthesia in 5 rats over at least 1 month (maximum: 121 days). Analysis showed that the characteristics of both spontaneous and odorant-evoked activity in M/B neurons remain stable over extended periods. This finding is significant for research aimed at developing biohybrid sensory system technologies for identifying target substances at ultra-low concentrations.
P. O. Kosenko (Wed,) studied this question.