scholarly journals Olfactory Deprivation and Enrichment: An Identity of Opposites?

2020 ◽  
Author(s):  
Emily Fitzwater ◽  
David M Coppola
Keyword(s):  
Inbred Mice ◽  
Sensory Information ◽  
Isovaleric Acid ◽  
Timing Recovery ◽  
Induction Effect ◽  
Olfactory Responses ◽  
Onset Timing ◽  
Classical Studies ◽  
Human Odor ◽  
Outbred Mice

Abstract The effects of deprivation and enrichment on the electroolfactogram of mice were studied through the paradigms of unilateral naris occlusion and odor induction, respectively. Deprivation was shown to cause an increase in electroolfactogram amplitudes after 7 days. We also show that unilateral naris occlusion is not detrimental to the gross anatomical appearance or electroolfactogram of either the ipsilateral or contralateral olfactory epithelium even after year-long survival periods, consistent with our previous assumptions. Turning to induction, the increase in olfactory responses after a period of odor enrichment, could not be shown in CD-1 outbred mice for any odorant tried. However, consistent with classical studies, it was evident in C57BL/6J inbred mice, which are initially insensitive to isovaleric acid. As is the case for deprivation, enriching C57BL/6J mice with isovaleric acid causes an increase in their electroolfactogram response to this odorant over time. In several experiments on C57BL/6J mice, the odorant specificity, onset timing, recovery timing, and magnitude of the induction effect were studied. Considered together, the current findings and previous work from the laboratory support the counterintuitive conclusion that both compensatory plasticity in response to deprivation and induction in response to odor enrichment are caused by the same underlying homeostatic mechanism, the purpose of which is to preserve sensory information flow no matter the odorant milieu. This hypothesis, the detailed evidence supporting it, and speculations concerning human odor induction are discussed.

scholarly journals Comparison of the Susceptibilities of C57BL/6 and A/J Mouse Strains to Streptococcus suis Serotype 2 Infection

2008 ◽  
Vol 76 (9) ◽  
pp. 3901-3910 ◽  
Author(s):  
María de la Cruz Domínguez-Punaro ◽  
Mariela Segura ◽  
Danuta Radzioch ◽  
Serge Rivest ◽  
Marcelo Gottschalk
Keyword(s):  
Septic Shock ◽  
Inbred Mice ◽  
Late Phase ◽  
Streptococcus Suis ◽  
Mouse Strains ◽  
Necrosis Factor Alpha ◽  
Central Nervous System Damage ◽  
Proinflammatory Mediators ◽  
Outbred Mice

ABSTRACT Streptococcus suis is an important swine and human pathogen. Assessment of susceptibility to S. suis using animal models has been limited to monitoring mortality rates. We recently developed a hematogenous model of S. suis infection in adult CD1 outbred mice to study the in vivo development of an early septic shock-like syndrome that leads to death and a late phase that clearly induces central nervous system damage, including meningitis. In the present study, we compared the severities of septic shock-like syndrome caused by S. suis between adult C57BL/6J (B6) and A/J inbred mice. Clinical parameters, proinflammatory mediators, and bacterial clearance were measured to dissect potential immune factors associated with genetic susceptibility to S. suis infection. Results showed that A/J mice were significantly more susceptible than B6 mice to S. suis infection, especially during the acute septic phase of infection (100% of A/J and 16% of B6 mice died before 24 h postinfection). The greater susceptibility of A/J mice was associated with an exaggerated inflammatory response, as indicated by their higher production of tumor necrosis factor alpha, interleukin-12p40/p70 (IL-12p40/p70), gamma interferon, and IL-1β, but not with different bacterial loads in the blood. In addition, IL-10 was shown to be responsible, at least in part, for the higher survival in B6 mice. Our findings demonstrate that A/J mice are very susceptible to S. suis infection and provide evidence that the balance between pro- and anti-inflammatory mediators is crucial for host survival during the septic phase.

scholarly journals CD-1 Outbred Mice Produce Less Variable Ultrasonic Vocalizations Than FVB Inbred Mice, While Displaying a Similar Developmental Trajectory

2021 ◽  
Vol 12 ◽  
Author(s):  
Matthew S. Binder ◽  
Hannah D. Shi ◽  
Angelique Bordey
Keyword(s):  
Maternal Care ◽  
Inbred Mice ◽  
Mean Amplitude ◽  
Developmental Trajectory ◽  
Ultrasonic Vocalizations ◽  
Neurological Deficits ◽  
Male And Female ◽  
Outbred Mice ◽  
Cd1 Mice ◽  
Relative Variability

The production of ultrasonic vocalizations (USVs) in neonatal mice is a critical means of communication that is used to elicit maternal care. Alterations in neonatal USV production is also an indicator of neurological deficits. However, USVs have been predominately assessed in inbred animals and are significantly understudied in outbred mice, even though outbred animals better represent the genetic diversity of humans and are used in several neurological disorder models. To determine the reproducibility of USVs across models, we compared male and female CD-1 (outbred) and FVB (inbred) mice on postnatal days (PD) 4, 8, 12, 16, and 20. We found that CD-1 and FVB mice displayed a similar developmental trajectory of USVs. However, CD1 mice emitted more USVs on PD 12 than FVB mice. In addition, FVB mice emitted a longer duration of calls on PD 4 and 8 and a higher overall maximum and minimum frequency of USVs than CD-1 mice. No differences in mean amplitude were found between groups. We also detected numerous significant differences between outbred and inbred mice when comparing each group's call composition. We next assessed the relative variability of mouse vocalizations between groups, finding that outbred mice were less variable than inbred mice. For the spectral and temporal characteristics of the USVs, variability was similar between groups. Altogether, we found that CD-1 outbred mice display a similar, if not lower, degree of variability than FVB inbred mice when assessing neonatal USVs.

scholarly journals Avoidance of the plant hormone cis-jasmone by Aedes aegypti depends on mosquito age in both plant and human odor backgrounds

2021 ◽  
Author(s):  
Jetske Gudrun de Boer ◽  
Aron P.S. Kuiper ◽  
Joeri Groot ◽  
Joop J.A. van Loon
Keyword(s):  
Aedes Aegypti ◽  
Mosquito Species ◽  
Lima Bean ◽  
Olfactory Response ◽  
Metabolic Energy ◽  
Young Females ◽  
Olfactory Responses ◽  
Bean Plants ◽  
Human Odor ◽  
Solvent Control

Abstract Adults of many mosquito species feed on plants to obtain metabolic energy and to enhance reproduction. Mosquitoes primarily rely on olfaction to locate plants and are known to respond to a range of plant volatiles. We studied the olfactory response of the yellow fever mosquito Aedes aegypti to methyl jasmonate (MeJA) and cis-jasmone (CiJA), volatile compounds originating from the octadecanoid signaling pathway that plays a key role in plant defense against herbivores. Specifically, we investigated how Ae. aegypti of different ages responded to elevated levels of CiJA in two attractive odor contexts, either derived from Lima bean plants or from human skin. Aedes aegypti females landed significantly less often on a surface with CiJA and MeJA compared to the solvent control, CiJA exerting a stronger reduction in landing than MeJA. Odor context (plant or human) had no significant main effect on the olfactory responses of Ae. aegypti females to CiJA. Mosquito age significantly affected the olfactory response, older females (7–9 d) responding more strongly to elevated levels of CiJA than young females (1–3 d) in either odor context. Our results show that avoidance of CiJA by Ae. aegypti is independent of odor background, suggesting that jasmonates are inherently aversive cues to these mosquitoes. We propose that avoidance of plants with elevated levels of jasmonates is adaptive to mosquitoes to reduce the risk of encountering predators that is higher on these plants, i.e. by avoiding ‘enemy-dense-space’.

scholarly journals Expression of Herpes Simplex Virus Thymidine Kinase in Toxoplasma gondii Attenuates Tachyzoite Virulence in Mice

1999 ◽  
Vol 67 (10) ◽  
pp. 5292-5297 ◽  
Author(s):  
Jay R. Radke ◽  
Michael W. White
Keyword(s):  
Cell Culture ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Toxoplasma Gondii ◽  
Thymidine Kinase ◽  
Inbred Mice ◽  
Lethal Challenge ◽  
Gene Copies ◽  
Outbred Mice ◽  
Simplex Virus

ABSTRACT We tested the virulence in mice of Toxoplasma gondii RH strain tachyzoites containing various copies of the chloramphenicol acetyl transferase-herpes simplex virus thymidine kinase fusion sequence (CAT-HSTK). Tachyzoite isolates containing ≥five copies of the fusion sequence were not lethal to female CD-1 outbred or BALB/c inbred mice, at doses up to 106 parasites, while the parental RH strain caused 100% mortality within 2 weeks at doses as low as 10 parasites. Mice infected with CTK11, an isolate containing five copies of the fusion sequence, showed no overt symptoms of disease and were protected from lethal challenge with the parental RH strain. The CTK11 isolate showed no difference in growth rate, the rate of host cell invasion, or extracellular viability in cell culture compared with parental RH parasites, demonstrating that the CAT-HSTK fusion protein does not affect the normal viability of this isolate. B11, B11C, and D1 isolates contained one or two copies of the CAT-HSTK coding sequence, were not sensitive to thymidine in cell culture, and caused 100% mortality in CD-1 outbred mice in <12 days. A fourth isolate, D1C, contained seven copies of the CAT-HSTK fusion sequence and was sensitive to exogenous thymidine (50% inhibitory concentration = 5.5 μM). Mice infected with D1C showed no symptoms of disease and survived beyond 90 days, thus correlating increased CAT-HSTK gene copies with thymidine sensitivity in cell culture and attenuated virulence in mice. BALB/c mice containing a targeted disruption of the gamma interferon gene (gko) were also susceptible to infection with CTK11 parasites but could be rescued by administration of subcutaneous thymidine once each day for 5 or 10 days following infection. These results suggest that the attenuation of CAT-HSTK+ isolates in mice is directly due to active thymidine kinase that likely alters the pyrimidine biosynthetic pathway in these parasites.

Immunological aspects ofGiardia murisandSpironucleus murisinfections in inbred and outbred strains of laboratory mice: a comparative study

Parasitology ◽  
1982 ◽  
Vol 85 (1) ◽  
pp. 85-99 ◽  
Author(s):  
Sara J. Brett ◽  
F. E. G. Cox
Keyword(s):  
Small Intestine ◽  
Anterior Part ◽  
Inbred Mice ◽  
Laboratory Mice ◽  
Parasite Resistance ◽  
Villus Height ◽  
Rate Of Recovery ◽  
Outbred Mice ◽  
Epithelial Lymphocyte ◽  
Giardia Muris

SUMMARYThe intestinal flagellates,Giardia murisandSpironucleus muris, cause similar infections in CBA mice as determined by trophozoite and cyst counts. Both parasites occur all along the small intestine withG. muris, being mainly present in the anterior part andS. muristowards the posterior. The early stages of infection are similar in all strains of mice examined and peak levels of both trophozoites and cysts occur 1–2 weeks after infection. All strains of mice overcome the infection but the rate of recovery varies considerably between strains, being most rapid in BALB/c and slowest in A and C57BL.B10. Outbred mice are more variable in their recovery than inbred mice. After recovery, mice are partially resistant to reinfection with the homologous but not the heterologous parasite. Resistance to reinfection withS. murisis greatest in those strains that eliminate the primary infection most rapidly.Giardia murisandS. muriscause similar changes in the mucosa of the small intestine of BALB/c mice with increased intra-epithelial lymphocyte counts from 3 weeks onwards corresponding with the start of the elimination of the parasites from the gut. A reduction in villus height and increase in crypt depth is also characteristic of these infections.

scholarly journals Avoidance of the Plant Hormone Cis-Jasmone by Aedes aegypti Depends On Mosquito Age in Both Plant and Human Odor Backgrounds

2021 ◽  
Vol 47 (8-9) ◽  
pp. 810-818
Author(s):  
Jetske G. de Boer ◽  
Aron P. S. Kuiper ◽  
Joeri Groot ◽  
Joop J. A. van Loon
Keyword(s):  
Aedes Aegypti ◽  
Mosquito Species ◽  
Lima Bean ◽  
Olfactory Response ◽  
Metabolic Energy ◽  
Young Females ◽  
Olfactory Responses ◽  
Bean Plants ◽  
Human Odor ◽  
Solvent Control

AbstractAdults of many mosquito species feed on plants to obtain metabolic energy and to enhance reproduction. Mosquitoes primarily rely on olfaction to locate plants and are known to respond to a range of plant volatiles. We studied the olfactory response of the yellow fever mosquito Aedes aegypti to methyl jasmonate (MeJA) and cis-jasmone (CiJA), volatile compounds originating from the octadecanoid signaling pathway that plays a key role in plant defense against herbivores. Specifically, we investigated how Ae. aegypti of different ages responded to elevated levels of CiJA in two attractive odor contexts, either derived from Lima bean plants or human skin. Aedes aegypti females landed significantly less often on a surface with CiJA and MeJA compared to the solvent control, CiJA exerting a stronger reduction in landing than MeJA. Odor context (plant or human) had no significant main effect on the olfactory responses of Ae. aegypti females to CiJA. Mosquito age significantly affected the olfactory response, older females (7–9 d) responding more strongly to elevated levels of CiJA than young females (1–3 d) in either odor context. Our results show that avoidance of CiJA by Ae. aegypti is independent of odor background, suggesting that jasmonates are inherently aversive cues to these mosquitoes. We propose that avoidance of plants with elevated levels of jasmonates is adaptive to mosquitoes to reduce the risk of encountering predators that is higher on these plants, i.e. by avoiding ‘enemy-dense-space’.

Relation Between Level of Prefrontal Activity and Subject's Performance

1999 ◽  
Vol 13 (2) ◽  
pp. 117-125 ◽  
Author(s):  
Laurence Casini ◽  
Françoise Macar ◽  
Marie-Hélène Giard
Keyword(s):  
Brain Activity ◽  
Sensory Information ◽  
Practice Phase ◽  
Trained Subjects ◽  
Anagram Task ◽  
Economic Information ◽  
Long Duration ◽  
Level Of Activity ◽  
The Brain ◽  
Processing Mechanism

Abstract The experiment reported here was aimed at determining whether the level of brain activity can be related to performance in trained subjects. Two tasks were compared: a temporal and a linguistic task. An array of four letters appeared on a screen. In the temporal task, subjects had to decide whether the letters remained on the screen for a short or a long duration as learned in a practice phase. In the linguistic task, they had to determine whether the four letters could form a word or not (anagram task). These tasks allowed us to compare the level of brain activity obtained in correct and incorrect responses. The current density measures recorded over prefrontal areas showed a relationship between the performance and the level of activity in the temporal task only. The level of activity obtained with correct responses was lower than that obtained with incorrect responses. This suggests that a good temporal performance could be the result of an efficacious, but economic, information-processing mechanism in the brain. In addition, the absence of this relation in the anagram task results in the question of whether this relation is specific to the processing of sensory information only.

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