Gene knockout experiments were conducted to identify the neuronal populations in both the PNS and CNS that were affected by the loss of different neurotrophins during development and the extent to which these populations were affected . trigeminal ganglia, nodose petrosal ganglia and cochlear ganglia.
12.
Wright, 1957, subsequently described " Neocardioceras " as evolute, compressed, with sharp umbilical and double ventrolateral tubercles ( inner and outer per side ) and a row of close round siphonal ( mid ventral ) tubercles that tend to form a nodose keel ( " Questedtoceras " comparison of Spath ).
