Changes

==Olfactory Communication==

==Olfactory Communication==

Scent signals are persistent, localised and indirect. They cannot be removed by the signaller once they have been deposited and thus they can convey information about the presence of the signaller that may be to its detriment. For example, rodents have been shown to exhibit unconditioned fear and avoidance behaviour in response to feline odours<ref>Dielenberg, R.A., Hunt, G.E., McGregor, I.S. (2001) When a rat smells a cat': The distribution of Fos immunoreactivity in rat brain following exposure to a predatory odor. ''Neuroscience''. 104(4), 1085-1097.</ref>. In a further twist, ''[[Toxoplasma gondii]]'' infection in rodents has been shown to have a highly specific effect on this aversive response, producing not just a loss of fear of feline urine pheromone odours, but also an attraction to them<ref>Vyas, A., Kim, S., Giacomini, N., Boothroyd, J.C.,. Sapolsky, R.M., (2007) Behavioral changes induced by Toxoplasma infection of rodents are highly specific to aversion of cat odors. ''PNAS''. 104(5), 6442-6447.</ref>. This enables parasite to continue its life cycle by infection of its feline definitive host. The behavioural changes seen are completely specific to feline odours, with other fear and conditioning responses remaining unaffected. Scent signals can also carry a considerable distance, as is the case in urinary scent marks by females during the reproductive season.  

Scent signals are localised, persistent and offer only an indirect form or communication. They cannot be removed by the signaller once they have been deposited and thus they can convey information about the presence of the signaller that may be to its detriment. For example, rodents have been shown to exhibit unconditioned fear and avoidance behaviour in response to feline odours<ref>Dielenberg, R.A., Hunt, G.E., McGregor, I.S. (2001) When a rat smells a cat': The distribution of Fos immunoreactivity in rat brain following exposure to a predatory odor. ''Neuroscience''. 104(4), 1085-1097.</ref>. In a further twist, ''[[Toxoplasma gondii]]'' infection in rodents has been shown to have a highly specific effect on this aversive response, producing not just a loss of fear of feline urine pheromone odours, but also an attraction to them<ref>Vyas, A., Kim, S., Giacomini, N., Boothroyd, J.C.,. Sapolsky, R.M., (2007) Behavioral changes induced by Toxoplasma infection of rodents are highly specific to aversion of cat odors. ''PNAS''. 104(5), 6442-6447.</ref>. This enables parasite to continue its life cycle by infection of its feline definitive host. The behavioural changes seen are completely specific to feline odours, with other fear and conditioning responses remaining unaffected. Scent signals can also carry a considerable distance, as is the case in urinary scent marks by females during the reproductive season.  

Olfactory communication involves the deposition of scent marks in the environment to convey a signal indirectly to another individual. Scent signals carry both information and meaning. Apart from providing other cats with information about ownership and usage of territory, scent marks also convey information about the identity of the depositor, its sex, health and reproductive status. This enables more complex [[Feline Social Behaviour|social organisation]] than merely avoidance, with cats choosing to avoid an area or attempt to gain control of it, depending on the threat posed by the current resident and the need to gain access to the resources included in that area.  

Olfactory communication involves the deposition of scent marks in the environment to convey a signal indirectly to another individual. Scent signals carry both information and meaning. Apart from providing other cats with information about ownership and usage of territory, scent marks also convey information about the identity of the depositor, its sex, health and reproductive status. This enables more complex [[Feline Social Behaviour|social organisation]] than merely avoidance, with cats choosing to avoid an area or attempt to gain control of it, depending on the threat posed by the current resident and the need to gain access to the resources included in that area.