Communication and Pheromones in Mammals

Human Communication Language Facial Expressions Gestures Tone of Voice Literal meaning of words, comprehension Facial Expressions Mood, emotional status Gestures Level of intensity, urgency May contain commands Tone of Voice Intent, emotional status

Animals and even human infants respond to tone of voice long before they comprehend the meaning of words

Failure of non-verbal communication in autistic children 80% of autistic children fail to answer the question correctly and instead point to the box.

Non-verbal intelligence in autism improves with vitamin D supplement John Cannell hypothesis that autism is caused by vitamin D deficiency.

Pheromones Subconscious communication Animals have a special pheromone detecting system-the Vomeronasal Organ (VNO) Humans are susceptible to many of the same original pheromone effects described in animals Bruce, Lee-Boot, Vandenburgh Effects Often related to sexual behaviors Bruce-abortion induced by new male odor Lee-Boot-synchronized menstrual cycles Vandenburgh-early onset of puberty in females exposed to unfamiliar male pheromones

VNO receptor responses to cues Exposed to male, female, or heterospecific (other species) cues. Very little overlap, especially in the class 2 VRs. Used fos staining to identify recently active cells in the VNO Isogai et al 2011 Nature

Identification of mouse ESP1 pheromone receptor, V2Rp5 ESP1=exocrine secreting gland peptide 1 is released in male tears and stimulates vno neurons in female mice. Used c-fos reactivity combined with ish for all v2r’s in response to esp-1. found all activated neurons were v2rp5 positive.

ESP1-V2Rp5 interaction is necessary for female receptivity

Circuit for female lordosis Haga et al, 2010 Nature

Scent marks are deposited according to lifestyle in wild mice P. Californicus is monogamous and territorial, which P. Leucopus is polygamous and non-territorial. Dark gray bars=pair housed animals, light gray=group housed virgin males Marking goes up for both paired and single males when confronted with a male odor—territorial Marking goes up only for single males when confronted with a female odor—mate attraction Unbonded single control males don’t mark much at all, as they don’t have a territory or female to defend/attract Becker et al, 2010

Female elephants signal estrous phase via pheromones in dung Male sniff frequency on the y axis, comparing females in the follicular phase (pre-ovulate) to the luteal phase (post-ovulate)

Summary of male sniff responses toward staged female dung Black: follicular phase (fertile) Hatched: luteal phase (post-fertile) White: control Ghosal et al 2012

Females distinguish between odor of dominant and subordinate males F-Msub/dom means she was exposed previously to subordinate or dominant male pheromones, bars represent sniffing or neurogenesis in response to actual sub or dom males. AraC inhibits neural proliferation.

Male pheromones (dominant only) induce neurogenesis in females Mak et al 2008

The assay for food preference learning

GC-D signaling components are required for food preference learning Cnga=cyclic nucleotide gated channel Gucy2d=guanylyl cyclase (makes cGMP) Both are in the same pathway for CO detection and food learning. Munger et al, 2010

A mouse circuit for learning about safe food Integration of food odors with CO from breath of trusted conspecific.

Responses of MOE to CS2 (optional) B6-control strain of mice Gucy2d-/-: mice lacking a guanyl cyclase (GC, makes cGMP) necessary for signaling the response to carbon disulfide Cnga3-/-: mice lacking a cyclic nucleotide gated channel that opens in response to cGMP/odor sensing Car2n: mice lacking carbonic anhydrase, helps metabolize CS2, necessary for some functions of OSNs Conclude GC-D+ OSNs are exquisitely sensitive chemosensors, responding to submicromolar levels of CS2 and to picomolar concentrations of guanylin family peptides

Responses of GC-D neurons to CS2 AZ is a carbonic anhydrase inhibitor (optional)

Humans may detect reproductive compatibility via pheromones Red: MHC similar Blue: MHC dissimilar Left side-session 1, right side-session 2, half the people started using the pill, see a decrease in preference for MHC dissimilar men No explanation for why the red bar isn’t higher in the first round of the study Figure 3. Mean difference in odour desirability ratings for MHC-dissimilar and MHC-similar men by women before (session I; red bar) and during (session II, blue bar) the use of oral contraceptive pill. Positive scores indicate preferences for MHC- dissimilar odours. In session I, none of the women were using the pill, and in session II, 60 had started using the pill whereas 40 had not. A decreasing preference for dissimilarity across the two sessions was observed among the pill- using group and, to a lesser extent, an increasing preference for dissimilarity in the control group. This suggests that pill use disrupts preferences for genetically dissimilar men at MHC loci. Adapted, with permission, from Ref. [39].

Female pheromones influence male behavior Solid line-control Dashed-on birth control Tip earnings by lap dancers