Living and Adapting to Its Own Habitat - Building the Most Complex Structure on Earth - page 228

Stimulus

Neural processing

Reception
of the
stimulus

Brain

Chemical output
of the processing

Release of
the
neurohormone

Activation of
the specific
signal cascade

Epigenetic change in the
gamete (cytoplasmic factor,
imprinted gene, centrosome,
cytoskeleton, etc.)

Epigenetic change in
a specific neural circuit
of the embryo

Induction of the
transgenerational change
Embryo

Figure 4.16 Diagrammatic representation of the “stimulus detour” mechanism of the
induction of transgenerational developmental change. The neural reception of the stimulus
and its processing in the neural circuit results in a chemical that induces the secretion of a
neurohormone, which activates a specific signal cascade leading to an adaptive epigenetic
change in gamete(s). The neural manipulation of the stimulus establishes a previously
nonexisting causal relationship between the stimulus and the signal cascade that causes the
transgenerational change.
Source : From Cabej (2012, p. 396) .

Receiving the stimulus (i.e., visual, olfactory, tactile, and auditory), the sensory
receptors/organs transform it into an electrical message. It is in this form that they
transmit it to a specific center in the CNS. The brain then leads the encoded stimu-
lus through a labyrinthine chain of connections across various centers for carrying
out the neural processing ( Figure 4.16 ). In the meantime, the involved neural cir-
cuits reconfigure their synaptic morphology ( Choi et al., 2005 ), resulting in the mod-
ification of computational properties of neural circuits and specific changes in the
chemical output ( Getting, 1989 ).