Q14 Why do dogs have a more sensitive and discriminating sen

Q14. Why do dogs have a more sensitive and discriminating sense of smell than humans?

Solution

The olfactory sense of dogs is very much sensitive than humans, and they depend more on olfaction than vision like most of the other mammals. But humans are unusual among other mammals, and we depend more on vision than olfaction for sense.

The major disparity of olfaction capacity varies with respect to brain perception and sensation between dogs and humans. Humans have less strong capability of olfactory information processing in the olfactory cerebral cortex with low interconnecting synapses compared to olfactory synapses existing in dogs. Thereby transfer olfactory information via bipolar neurons is much higher in dogs for the perception of smell. Olfactory cortex of dogs 40 times bigger than humans with a lot of interconnecting synapses.

Mechanism:

The reduction in depolarization trigger action potential is lower in olfactory sensory neurons (OSN) in the presence of “prolonged stimulus with odorant exposure” result in an adaptation mechanism. This is leading to low level of cAMP with reduction in “olfactory sensory neuronal perception” due to desensitization. This step in the odor transduction pathway of GPCR is altered to elicit adaptation. This desensitization is mainly due to upstream activity of cAMP that involves Ca²⁺ dependent mechanism