Smell and the BrainOdorous substances, including plant-derived fragrances, induce various physiological, emotional, and behavioural responses in human and other mammalian species

Odorous substances, including plant-derived fragrances, induce various physiological, emotional, and behavioural responses in human and other mammalian species

Smell and the BrainNeuronal impulses conduct along the olfactory tract to: prepiriform cortex, limbic system, thalamus and much moreComplex interconnected networks are responsible for many behaviours:eating, affective, sexual and reflexes like salivation (trigeminal n.)

Neuronal impulses conduct along the olfactory tract to: prepiriform cortex, limbic system, thalamus and much more

Complex interconnected networks are responsible for many behaviours:

eating, affective, sexual and reflexes like salivation (trigeminal n.)

Plant Derived ChemicalsHave long been utilised as holistic relaxants in aromatherapy and complementary medicineOnly recently have their physiological mechanisms been investigatedPraescentTMalpha-pinene trans-2-hexenalcis-3-hexen-1-ol

Have long been utilised as holistic relaxants in aromatherapy and complementary medicine

Only recently have their physiological mechanisms been investigated

Alleviating Effects of Plant-Derived Fragrances on Stress-Induced Hyperthermia in RatsBy Akutsuet alPresented by Aaron Sparshott

IntroductionInvestigated the effects of exposure to plant-derived odours on the autonomic and behavioural responses to novel environment in rats.A transient increase of body temperature has been shown to be a typical and reproducible autonomic response to various physical as well as psychological stressors.This response is often referred to as stress induced hyperthermia or emotional fever.

Investigated the effects of exposure to plant-derived odours on the autonomic and behavioural responses to novel environment in rats.

A transient increase of body temperature has been shown to be a typical and reproducible autonomic response to various physical as well as psychological stressors.

This response is often referred to as stress induced hyperthermia or emotional fever.

What they did...Rats were moved to a novel environment, by being transferred to an unfamiliar cage with a certain odour present.42 Rats in Total: Alpha-pinene, Lavender and Green Odourcages were each presented with 12 rats. Control Group ratswere placed back in original cage after handling.Half of each odour group (n=6) except control, were exposed to solvent only.1212126

Rats were moved to a novel environment, by being transferred to an unfamiliar cage with a certain odour present.

42 Rats in Total: Alpha-pinene, Lavender and Green Odourcages were each presented with 12 rats. Control Group ratswere placed back in original cage after handling.

Half of each odour group (n=6) except control, were exposed to solvent only.

Biosignals and BehaviourHeart Rate and Temperature were monitored using a bio-signal transmitter implanted a week prior to experimentation.Behavioural Analysis via video camera.SniffingRearingGroomingRestingGeneral Activity

Heart Rate and Temperature were monitored using a bio-signal transmitter implanted a week prior to experimentation.

Behavioural Analysis via video camera.

Sniffing

Rearing

Grooming

Resting

General Activity

What they discovered...Green Odour accelerated the declining phase of body temperatureAlpha-pinene suppressed stress-induced hyperthermia from the beginningTemperature Difference (oC)Time (min)

Green Odour accelerated the declining phase of body temperature

Alpha-pinene suppressed stress-induced hyperthermia from the beginning

What they discovered...Exposure to any of the three fragrances made no significant difference to Heart Rate∆ BPMTime (min)No significant differences in behaviour were observed as a result of any fragrance

Exposure to any of the three fragrances made no significant difference to Heart Rate

No significant differences in behaviour were observed as a result of any fragrance

What does it mean?Body Temperature rose as a result of being moved to a novel environment, reflected as a stress-induced hyperthermia response.Previous studies have shown that stress-induced hyperthermia responses can be attenuated by pretreating the subject with centrally acting drugs such as;noradrenalineβ receptor antagonist,vasopressin, prostaglandin inhibitors5-HT1A receptor agonists

Body Temperature rose as a result of being moved to a novel environment, reflected as a stress-induced hyperthermia response.

Previous studies have shown that stress-induced hyperthermia responses can be attenuated by pretreating the subject with centrally acting drugs such as;

noradrenalineβ receptor antagonist,

vasopressin,

prostaglandin inhibitors

5-HT1A receptor agonists

What does it mean?In the present study, the rats were exposed to odorants without being given any severe stress, and the exposure to the green odour or the alpha-pinene was found to have alleviating effects of the stress-induced hyperthermia.However it would appear that the mechanism of alleviation differs between the two odours.

In the present study, the rats were exposed to odorants without being given any severe stress, and the exposure to the green odour or the alpha-pinene was found to have alleviating effects of the stress-induced hyperthermia.

However it would appear that the mechanism of alleviation differs between the two odours.

Other points of interestHeart Rate might be a less sensitive parameter as compared with the Body Temperature for detecting the possible alleviating effects of fragrances on stress responses‘Sedative effects’ of lavender in human’s are more likely to be a psychological property rather than physiological.Autonomic responses showed no significant difference to controlNo observed change in behaviour.

Heart Rate might be a less sensitive parameter as compared with the Body Temperature for detecting the possible alleviating effects of fragrances on stress responses

‘Sedative effects’ of lavender in human’s are more likely to be a psychological property rather than physiological.

Autonomic responses showed no significant difference to control

No observed change in behaviour.

Summing UpBy recording autonomic and behavioural parameters from unrestrained rats, Akutsu et al found that the green odour and alpha-pinene have anti-stress potency, namely that they exerted alleviating effects on stress-induced hyperthermia.

Attenuation of Stress-Induced Elevations in Plasma ACTH Level and Body Temperature in Rats by Green OdourBy Nakashima et alPresented by Zoe Hutchins

IntroductionInvestigated the effect of green odour on plasma adenocorticotropic hormone (ATCH) and body temperature (Tb) of stress-induced ratsGREEN ODOURtrans-2-hexanal [0.03%]cis-3-hexenal [0.03%]

Investigated the effect of green odour on plasma adenocorticotropic hormone (ATCH) and body temperature (Tb) of stress-induced rats

Stress Response:Elevation of ACTH Level and TbHypothalamusAnterior PituitaryPreoptic CentreOlfactory Inputs↓ Tb↓ACTH

Method - ACTH MeasurementsRats were relocated and immobilised via restraint for 2 hoursControl: immobilisation without green odourTreatment: exposure to green odour at various times prior, during or following immobilisationBlood was collected and assayed for ACTH either immediately following immobilisation or 2 days later.STRESS1h1h½ h0h2h4h6h48hImmediate ACTHLong-Lasting ACTH

Rats were relocated and immobilised via restraint for 2 hours

Control: immobilisation without green odour

Treatment: exposure to green odour at various times prior, during or following immobilisation

Blood was collected and assayed for ACTH either immediately following immobilisation or 2 days later.

Results – ACTH LevelsGreen odour [0.03%] decreased ACTH levels when applied during or following immobilisation.

Method – Tb MeasurementsRats were implanted with telemetry transmitters and given 10 days to recover until ACTH levels stabilised.Tb was recorded every 20 minutes for 3 consecutive days.Treatment rats were exposed to green odour for 30 minutes during the beginning of the 2 hour immobilisation.Temperature Recording10 daysRecoveryStress (2hr)Day 1(Prior)Day 3(Post)Device ImplantationGreen Odour (½hr)

Rats were implanted with telemetry transmitters and given 10 days to recover until ACTH levels stabilised.

Tb was recorded every 20 minutes for 3 consecutive days.

Treatment rats were exposed to green odour for 30 minutes during the beginning of the 2 hour immobilisation.

Results – Tb RecordingGreen odour [0.03%] decreased Tb immediately after stress and during the light phase of the following day.

Methods - WeaknessesDuring immobilisation the odorous paper was held 3cm from the nose of the rat, however when applied before or after immobilisation, the paper was placed in a corner of the cage.Potential inconsistencies in the levels of green odour exposure the different groups received.IMMOBILISEDNON - IMMOBILISED

During immobilisation the odorous paper was held 3cm from the nose of the rat, however when applied before or after immobilisation, the paper was placed in a corner of the cage.

Potential inconsistencies in the levels of green odour exposure the different groups received.

Results SummaryGREEN ODOUR↓ ACTH↓ TbImmediately following stress & two days post-stressWhen applied during or following stress

Possible Mechanisms of ActionACTH Levels Hypothalamus & Catecholamine System↓ Fos in the Paraventricular Nucleus (PVN) down-regulating CRH secretion and subsequently ACTHTb Reduction↓ Sympathetic activity↓ ACTH and GlucocorticoidsFurther research is required to fully elucidate the physiologic mechanisms of green odour

ACTH Levels

Hypothalamus & Catecholamine System

↓ Fos in the Paraventricular Nucleus (PVN) down-regulating CRH secretion and subsequently ACTH

Tb Reduction

↓ Sympathetic activity

↓ ACTH and Glucocorticoids

Due to current unpublished work the remainder of this presentation is not available to slideshare.For more information regarding Praescent or SerenaScent go to

Due to current unpublished work the remainder of this presentation is not available to slideshare.

For more information regarding Praescent or SerenaScent go to