160 Self and the Phenomenon of Life
b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanity “9x6”- A post-synaptic potential may or may not lead to an action potential, but an
action potential, once formed, will self-propagate to the terminal of the axon. - The common neuromodulators are somatostatin, cholecystokinin (CCK),
oxytocin, vasopressin, vasoactive intestinal peptide (VIP), Substance P,
endorphin, neuropeptide Y (NPY), neurotensin, bradykinin, angiotensin,
and thyrotropin-releasing hormone (TRH). The non-peptide neuromod-
ulators include the endocannabinoids (lipids) and hydrogen sulfide (gas). - One exception is the hippocampus, which retains the 3-layer structure of a
primitive cortex. This suggests that the hippocampus is evolutionarily old. - Hebb HB. (1949) The Organization of Behavior. John Wiley.
- Berning S, Willig KI, Steffens H, et al. (2012) Nanoscopy in a living mouse
brain. Science 335: 551. - Sperry RW. (1963) Chemoaffinity in the orderly growth of nerve fiber pat-
terns and connections. Proc Natl Acad Sci USA 50: 703–710; Meyer RL.
(1998) Roger Sperry and his chemoaffinity hypothesis. Neuropsychologia
36: 957–980. - Hattori D, Millard SS, Wojtowicz WM, Zipursky SL. (2008) Dscam-
mediated cell recognition regulates neural circuit formation. Ann Rev Cell
Dev Biol 24: 597–620. - Fuerst PG, Bruce F, Tian M, et al. (2009) DSCAM and DSCAML1 func-
tion in self-avoidance in multiple cell types in the developing mouse retina.
Neuron 64: 484–497. - Yamagata M, Sanes JR. (2008) Dscam and Sidekick proteins direct lamina-
specific synaptic connections in vertebrate retina. Nature 451: 465–469. - Li HL, Huang BS, Vishwasrao H, et al. (2009) Dscam mediates remodeling
of glutamate receptors in Aplysia during de novo and learning-related syn-
apse formation. Neuron 61: 527–540. - Caution should be used when denoting a behavior as instinct. There is a
gray area between the learned and the inborn. What appears as instinct
may have a learned component upon scrutiny, such as imprinting in young
animals, which usually occurs at a critical period. - Inoue T, Kumamoto H, Okamoto K, et al. (2004) Morphological and func-
tional recovery of the planarian photosensing system during head regener-
ation. Zoolog Sci 21: 275–83. - Gong Z, Liu J, Guo C, et al. (2010) Two pairs of neurons in the central brain
control Drosophila innate light preference. Science 330: 499–502.