The concentration of glutamate in cerebral tissue as a factor for the assessment of the emotional state before death. A preliminary report

Olfactory and tissue markers of fear in mammals including humans

Pheromones are a mysterious world of chemical signals involved in conspecific communication. They play a number of key functions important for preservation of life of individual organisms, for their defence, survival of offspring and preservation of species. The best-known groups of pheromones include: trail pheromones, territorial pheromones, sex pheromones, aggregation pheromones, dispersion pheromones, repellent pheromones, social pheromones and alarm pheromones. Alarm pheromones are pheromones that are emitted by animals in threatening situations and inform members of the same species of danger. The identified alarm pheromones are synthesised by insects and aquatic organisms. Also humans are able to emit and perceive pheromones. Although alarm pheromones have not been isolated and identified in man so far, there is presumably evidence for their presence in humans. Pinpointing human alarm pheromones, determinants of experienced stress and inductors of provoked fear could have widespread consequences. Their identification could also be of significant importance for the practical utilisation of results by institutions responsible for safety and defence as well as law enforcement/crime detection and antiterrorist activities.

The post-mortem concentration of glutamate in the structures of rat brain as an exponent of short aversive sensory stimulation preceding death

The problem of post-mortem assessment of short central fear reaction preceding death has been obscure till now. The preliminary results obtained by authors have encouraged them to further research on this topic. Time of aversive sensory stimulation in the presented study was considerably decreased in comparison to the preliminary investigations. The concentration of glutamate was assayed in the selected structures of limbic system and in the cerebellum. The rats were subjected to different simultaneous modalities of sensory stimulation. The involvement of the hippocampi and the cerebellum was revealed as measured by glutamate concentration increase in the whole structures homogenates. The dominant role of mechanical stimulus has been suggested based on the measured increase of glutamate concentration in the whole cerebellum homogenate. By using the presented experimental paradigm a possible application of the biochemical assessment of human brain tissue might be developed in the future for implementing in the field of forensic pathology. The biochemical evaluation of "frozen frames" of neurotransmission can possibly help reconstruct the events which had happened just before sudden and violent death.